A driving power supply for optical fiber laser and a power supply driving method thereof

Abstract

The present invention belongs to the technical field of optical fiber lasers, and is an energy-saving driving power supply for optical fiber lasers used in space communications and laser radars. It is characterized by: comprising: a central processing unit for controlling voltage output; a power module for providing voltage output; a digital analog signal conversion chip, wherein the central processing unit controls the current output of a voltage-controlled current source through the digital analog signal conversion chip; a voltage-controlled current source for providing power to a laser diode; a sampling feedback circuit for detecting a set current; an environmental sensing circuit for detecting the ambient temperature; and a signal receiving circuit for detecting the signal transmission effect. In the case where the performance of existing materials is difficult to significantly improve, the present invention can effectively reduce the energy consumption of optical fiber lasers for space communications and improve the endurance of the entire device.

Description

Technical Field

[0001] The invention belongs to the technical field of optical fiber lasers and is an energy-saving driving power supply for optical fiber lasers used in space communications and laser radars. Background Art

[0002] Fiber lasers originated from early fiber-optic communication networks. Since there is a matching power supply system and the output power of fiber lasers for communication applications is not high, there is no urgent need for energy saving of fiber lasers. However, for applications such as aerospace communications, drone lidar, and mobile laser communication equipment, fiber lasers are powered by batteries with limited capacity, and energy-saving drive power supplies become very important. The usual drive method has low efficiency and is difficult to meet the energy-saving requirements of fiber lasers.

[0003] Fiber lasers are generally pumped by laser diodes. The main function of the driver power supply is to provide a constant current source for the laser diode. Most of the driver power supply technologies focus on surge protection control [see "High-power fiber laser pump source LD driver power supply design", "Optoelectronic Technology Application", 2014 Volume 29, pages 70-74], temperature compensation ["High-power semiconductor laser constant current source design", "Optical Devices", 2008 Issue 1, pages 46-48], multi-mode output [CN201610513345.6], switching speed [CN201420241283.4], etc., and little consideration is given to how to save energy. The efficiency of the driver power supply is mainly obtained by multiplying the efficiency of the two parts of AC to DC and DC to constant current. The efficiency of these two parts is affected by conventional losses such as core loss, wire loss, device heating, and voltage drop. There are many technical solutions in conventional power supply technology, and it has approached the limit that existing materials can achieve. Further breakthroughs require the emergence of new materials. Summary of the invention

[0004] The present invention provides an energy-saving fiber laser driving power supply technology, which is characterized by combining a flexible driving power supply design and utilizing an intelligent algorithm to adjust the working state of the driving source according to the particularity of individual application scenarios, thereby reducing the energy consumption of the entire fiber laser.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A driving power supply for a fiber laser, comprising: a central processing unit, a DC conversion power supply 2, a digital analog signal conversion chip 3, a voltage-controlled current source 4, a sampling feedback circuit 5, an environment sensing circuit 6, and a signal receiving circuit 7;

[0007] The central processor controls the current output of the voltage-controlled current source 4 through the digital-to-analog signal conversion chip 3;

[0008] The DC conversion power supply 2 is a linear voltage-stabilized source structure with pulse width modulation, which provides the operating voltage for the laser diode 9;

[0009] The central processing unit controls the voltage-adjustable DC conversion power supply 2 through the digital potentiometer 8, and controls the frequency and duty cycle of the pulse width modulation signal output by the DC conversion power supply 2;

[0010] The voltage-controlled current source 4 provides working current for the laser diode 9 used for pumping the optical fiber in the optical fiber laser;

[0011] The sampling feedback circuit 5 is used to sample the working voltage and working current of the laser diode 9 and then feed back to the central processor;

[0012] The signal receiving circuit 7 is used to receive set parameter information;

[0013] The environment sensing circuit 6 collects the ambient temperature, the operating temperature of the laser diode 9, the working distance, the transmission light path scattering loss coefficient, and the output power parameters of the fiber laser through sensors and inputs them into the central processor, and compares them with the set parameter information received by the signal receiving circuit 7, and the comparison results are used for calculation.

[0014] Furthermore, the central processing unit is a digital signal processor DSP with high-speed data processing capability or a microcontroller MCU with built-in DSP.

[0015] A power supply driving method for a driving power supply of a fiber laser, characterized in that it comprises the following steps:

[0016] Step 1: Input the external position, temperature, received signal strength and other environmental parameters into the central processing unit through the signal receiving circuit 7; the central processing unit uses the neural network algorithm to analyze the input parameters and calculate the value of the control signal, which is used to control the output voltage of the digital analog signal conversion chip 3 and the resistance of the digital potentiometer 8; thereby controlling the voltage of the DC conversion power supply 2 and the current of the voltage-controlled current source 4, and finally accurately controlling the voltage and current of the laser diode 9 to achieve energy saving of the entire circuit. In this link, in order to further improve the control accuracy, a sampling feedback loop 5 is added to enhance the control response speed and control efficiency by using the PID (proportional-integral-differential) algorithm.

[0017] Step 2: The environment sensing circuit 6 collects the environment temperature, the working temperature of the laser diode 9, the working distance, the transmission light path scattering loss coefficient, and the fiber laser output power parameters through the sensor 15 and inputs them into the central processor, and compares them with the set parameter information received by the signal receiving circuit 7, and the comparison result is used for calculation;

[0018] Step 3: The CPU calculation method is:

[0019] It includes z layers of neural network, each layer of network contains n network nodes, the steps are as follows,

[0020] T1, communication distance, ambient temperature, signal return light intensity, communication rate and alignment error are used as input parameters x(1,5), and bit error rate is used as output parameter y;

[0021] T2, through the dynamic optimization of the neural network correlation parameter β (i = 1, n; j = 1, z), that is, considering that the β parameter is a function that changes with time, it is written into two parts during the optimization process: the time-containing part βt and the time-excluding part βa. For the time-containing part βt, the time translation average method is used to calculate the minimum root mean square value of its error. For the time-excluding part βa, the Gaussian elimination method is used to calculate the minimum root mean square value of its error. Finally, these two parts are added to obtain the neural network model determined by the correlation coefficient β matrix. This correlation coefficient matrix is ​​recorded in the memory as a practical energy-saving model; its optimization equation can be expressed as: y = {∏β(1, j)x(1, j)+∏β(2, j)x(1, j)+…}, and the optimal β (i = 1, n; j = 1, z) parameter is calculated through iteration to minimize Δy.

[0022] Step 4: The central processing unit outputs a digital control code to the digital analog signal conversion chip 3 to control the current output of the voltage-controlled current source 4; the central processing unit outputs a digital control code to the digital potentiometer 8 to control the voltage output of the voltage-adjustable DC conversion power supply 2;

[0023] Step 5: The sampling feedback circuit 5 samples the working voltage and working current of the laser diode 9 and feeds them back to the central processor;

[0024] Step 6: The central processing unit adjusts the control code to the digital-to-analog signal conversion chip 3 and the digital potentiometer 8 based on the sampled feedback signal combined with the PID (proportional-integral-differential) algorithm to improve the transient fluctuations in the voltage and current of the laser diode 9.

[0025] Beneficial effects of the present invention: Compared with the existing driving power supply technology, the present invention combines the flexible driving circuit design with the intelligent algorithm, and obtains the optimal output power of the fiber laser through the situational awareness of the fiber laser use environment, thereby achieving energy saving. This energy-saving method can effectively reduce the energy consumption of space communication fiber lasers and improve the endurance of the entire equipment when the performance of existing materials is difficult to significantly improve. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 .System diagram of fiber laser driver power supply based on intelligent energy-saving algorithm.

[0027] Figure 2 .Schematic diagram of a linear voltage regulator.

[0028] Figure 3 .Computational network structure diagram of intelligent algorithm.

[0029] Figure 4 .Schematic diagram of the driving power supply of the fiber laser used in intersatellite communication.

[0030] Figure 5 .The driving power supply of the fiber laser used in the lidar on the drone.

[0031] In the figure:

[0032] 1-digital signal processor, 2-DC conversion power supply, 3-digital analog signal conversion chip, 4-voltage-controlled current source, 5-sampling feedback circuit, 6-environmental sensing circuit, 7-signal receiving circuit, 8-digital potentiometer, 9-laser diode, 10-PWM pulse generation chip, 11-transformer coil, 12-field effect transistor, 13-voltage conversion module, 14-sampling and analog signal conversion chip, 15-sensor, 16-PWM controlled DC power supply, 17-rectifier circuit, 18-voltage stabilization circuit, 19-laser radar. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0034] The present invention consists of a flexible power supply hardware component and an intelligent energy-saving algorithm for fiber lasers. The basic hardware components are as follows: Figure 1 As shown, it includes the following components: the central processing unit is composed of a digital signal processor 1 (DSP) with high-speed data processing capability or a microcontroller (MCU) with built-in DSP, and is also equipped with a voltage-adjustable DC conversion power supply (DC / DC) 2, a digital analog signal conversion chip (DAC) 3, a voltage-controlled current source 4, a sampling feedback circuit 5, an environmental sensing circuit 6, and a signal receiving circuit 7. The laser diode 9 used to pump the optical fiber is powered by the voltage-controlled current source 4. Generally speaking, the application scenarios of energy-saving fiber lasers are not very complex, and the more complex intelligent algorithms themselves are extremely energy-consuming, so these two aspects are balanced. As Figure 3 As shown, the intelligent algorithm of the present invention is composed of 3-5 layers of neural networks, and each layer of the neural network contains only 5-10 nodes. This simple neural network algorithm is suitable for the capabilities of the digital signal processor 1, and does not require the use of an advanced operating system. The calculation speed can also meet the application of fiber lasers in different scenarios.

[0035] like Figure 2As shown, the voltage-adjustable DC conversion power supply 2 adopts a linear voltage-stabilizing source structure of pulse width modulation (PWM). The control signal output by the digital signal processor 1 controls the PWM pulse generating chip 10 to generate a PWM pulse signal with controllable pulse width. The PWM pulse signal controls the high-speed switching time of the field effect tube 12, and obtains the conversion voltage output through the transformer coil 11. The digital signal processor 1 can adjust the output voltage of the DC conversion power supply 2 through the digital potentiometer 8. And according to the different set output voltages, the digital signal processor 1 controls the frequency and duty cycle of the pulse width modulation signal to obtain the optimal voltage conversion efficiency.

[0036] The digital signal processor 1 controls the current output of the voltage-controlled current source 4 through the digital-to-analog signal conversion chip 3, thereby controlling the current injection of the fiber laser and ultimately adjusting the energy consumption of the fiber laser.

[0037] In the design of the flexible driving power supply, the sampling feedback circuit 5, the environment sensing circuit 6 and the signal receiving circuit 7 are used to detect the set current, the ambient temperature and the signal transmission effect, so as to determine whether the current driving current is appropriate and accurate.

[0038] The core of the present invention is to intelligently adjust the energy consumption of the fiber laser through the perception of multiple parameters of the working state. For fiber lasers used for space communication, the communication distance, ambient temperature, suspended matter in the laser transmission path, laser alignment accuracy, and communication coding all have an impact on the intensity of the laser signal. Traditionally, in order to ensure a good communication rate under the worst conditions, the laser output power is often set very high, which greatly increases the power consumption of the fiber laser. On the other hand, due to the complexity of the communication environment, it is very difficult to predict the laser output power of the laser under different working environments in advance. For this reason, in the present invention, a high-speed digital signal processor 1 and an intelligent algorithm are used, combined with a flexible drive source design, to achieve the appropriate fiber laser output power under different use environments and states, thereby ultimately reducing the power consumption of the fiber laser and achieving the purpose of energy saving.

[0039] The specific intelligent algorithm consists of 3-5 layers of neural network such as Figure 3As shown in the figure, each layer of the network contains only 5-10 network nodes. The communication distance, ambient temperature, signal return light intensity, communication rate and alignment error are used as input parameters x(1,5), and the bit error rate is used as the output parameter y. The laser output power is used as the adjustment parameter. By dynamically optimizing the neural network associated parameters β(i=1,5; j=1,5) [assuming there are 5 network nodes, β is the network associated parameter related to the laser power], a specific neural network model is obtained and recorded in the memory as a practical energy-saving model. The optimization equation can be expressed as: y={∏β(1,j)x(1,j)+∏β(2,j)x(1,j)+…}. Through iteration, the optimal β(i=1,5; j=1,5) parameters are calculated to minimize Δy. In order to reduce the computing load of the high-speed digital signal processor of the terminal, the initial optimization solution of the neural network can be executed in the central workstation. After obtaining the first-stage model, the high-speed digital signal processor of the terminal will make fine adjustments.

[0040] Embodiment 1: Driving power supply of optical fiber laser for intersatellite communication

[0041] like Figure 4 As shown, the digital signal processor 1 of the driving power supply in this embodiment adopts the DSP (high-speed digital signal processor) of the TMS320C5441 model of TI company, which has a 16-bit fixed-point number and a computing power of 532MIPS. The power conversion module 14 adopts the CQS24120-12 model DC / DC of COSEL company, whose input is 24V and outputs 12V / 12A DC. The voltage conversion module 13 can adjust the output voltage signal V1 through the output digital potentiometer 8. The current is adjusted by the digital output pin of the digital signal processor 1 outputting the voltage signal V2 through the digital analog signal conversion chip 3. The voltage signal V2 is adjusted to the output current I1 through the voltage-controlled current source 4.

[0042] The output voltage V1 and output current I1 are sampled by the sampling and analog signal conversion chip 14, converted into digital signals after passing through the AD conversion chip and then returned to the digital signal processor 1, which performs calculations according to the intelligent algorithm.

[0043] The environment sensing circuit 6 collects parameters such as the ambient temperature, the operating temperature of the laser diode 9, the working distance, the transmission light path scattering loss coefficient, the output power of the optical fiber laser, etc. through the sensor 15, and compares them with the received signal in the signal receiving circuit 7. The result is determined by the intelligent algorithm to adjust the voltage V1 and I1.

[0044] The power supply circuit includes conventional over-current, over-temperature and over-voltage protection circuit units.

[0045] The intelligent algorithm uses a back propagation (BP) neural network learning algorithm based on Bayesian regularization. The neural network is divided into 5 layers, each layer consists of 5 nodes. Through repeated learning in a simulated aerospace environment, the correction coefficient is 0.85, and the energy-saving efficiency is 15% higher than that of the drive power supply without intelligent algorithms, which has obvious energy-saving advantages.

[0046] Embodiment 2: Driving power supply of fiber laser for laser radar on unmanned aerial vehicle.

[0047] like Figure 5 As shown, due to the high complexity of the UAV flight environment, the digital signal processor 1 of the driving power supply in this embodiment is ADI's ADSP-BF542 with built-in artificial intelligence (AI) algorithm, with a floating-point operation speed of 1200MIPS and highly complex parallel processing capabilities. The power module is a PWM-controlled DC power supply 16, with an input range of 48-60V / 1A and an output of 5V / 5A. The digital signal processor 1 can generate a PWM signal for PWM-controlled output voltage and current of the DC power supply 16. After the PWM-controlled DC power supply 16, there is a rectifier circuit 17 and a voltage stabilizing circuit 18 for providing stable DC to the DSP and the operation circuit. The digital signal processor 1 outputs the set voltage through the control pin from the digital analog signal conversion chip (AD53X), and powers the laser diode 9 through the voltage-controlled current source 4. The voltage-controlled current source 4 is composed of a high-precision operational amplifier AD8502 and an N-channel MOSFET.

[0048] The driving power supply described in this embodiment also includes an environmental sensing circuit 6, including a temperature sensor, a GPS signal, map information, and a communication decoding circuit, which is used to obtain environmental information in the cloud. The intelligent algorithm calculates the output voltage and current of the driving power supply based on the measurement results of the laser radar 19 and the environmental sensing parameters to achieve the purpose of energy saving. This driving power supply can not only power the fiber laser, but also power the laser radar 19 and the data acquisition system to achieve a unified energy saving goal.

[0049] The intelligent algorithm uses the built-in AI function of DSP combined with the TensorFlow computing module to build a machine learning algorithm based on data flow, complete the large data volume calculation of 10-layer network and 50 nodes, and report the calculation results to the data center (cloud). First, the preliminary optimization is completed at the ground workstation to form a 10x50 optimized data matrix. After writing it into the central control chip, the back-end optimization is completed when the drone's laser radar 19 is working to achieve energy saving.

[0050] The implementation methods of the embodiments described above are only used to illustrate the present invention, and are not intended to limit the present invention. Any technician familiar with the technical field can make various modifications, changes or substitutions without departing from the technical scope disclosed by the present invention. Therefore, all equivalent and similar technical methods should be covered within the scope of patent protection of the present invention.

Claims

1. A driving power supply for a fiber laser, characterized in that: It includes a central processing unit, a DC conversion power supply (2), a digital analog signal conversion chip (3), a voltage-controlled current source (4), a sampling feedback circuit (5), an environment sensing circuit (6), and a signal receiving circuit (7); The central processing unit controls the current output of the voltage-controlled current source (4) through a digital-to-analog signal conversion chip (3); The DC conversion power supply (2) is a linear voltage-stabilized source structure with pulse width modulation, and provides an operating voltage for the laser diode (9); The central processing unit controls the voltage-adjustable DC conversion power supply (2) through a digital potentiometer (8), and controls the frequency and duty cycle of the pulse width modulation signal output by the DC conversion power supply (2); The voltage-controlled current source (4) provides an operating current for a laser diode (9) used for pumping an optical fiber in a fiber laser; The sampling feedback circuit (5) is used to sample the working voltage and working current of the laser diode (9) and then feed back the sampling to the central processing unit; The signal receiving circuit (7) is used to receive set parameter information; The environment sensing circuit (6) collects the environment temperature, the operating temperature of the laser diode (9), the operating distance, the transmission light path scattering loss coefficient, and the output power parameters of the optical fiber laser through the sensor and inputs them into the central processor, and compares them with the set parameter information received by the signal receiving circuit (7), and the comparison result is used for calculation.

2. The driving power supply of a fiber laser according to claim 1, characterized in that: The central processing unit is a digital signal processor (1) DSP with high-speed data processing capability or a microcontroller MCU with built-in DSP.

3. A power supply driving method for a fiber laser driving power supply, characterized in that : Includes the following steps: Step 1: Input environmental parameters including external position, temperature, and received signal strength into a central processing unit through a signal receiving circuit (7); the central processing unit uses a neural network algorithm to analyze the input parameters and calculate the value of a control signal, which is used to control the output voltage of a digital analog signal conversion chip (3) and the resistance value of a digital potentiometer (8); thereby controlling the voltage of a DC conversion power supply (2) and the current of a voltage-controlled current source (4), and ultimately accurately controlling the voltage and current of a laser diode (9), thereby achieving energy saving for the entire circuit; Step 2: The environment sensing circuit (6) collects the environment temperature, the working temperature of the laser diode (9), the working distance, the transmission light path scattering loss coefficient, and the output power parameters of the optical fiber laser through the sensor (15), and inputs them into the central processor, and compares them with the set parameter information received by the signal receiving circuit (7), and the comparison result is used for calculation; Step 3: The CPU calculation method is: It includes z layers of neural network, each layer of network contains n network nodes, the steps are as follows, T1, communication distance, ambient temperature, signal return light intensity, communication rate and alignment error are used as input parameters x(1,5), and bit error rate is used as output parameter y; T2, through the dynamic optimization of the neural network correlation parameter β (i = 1, n; j = 1, z), that is, considering that the β parameter is a function that changes with time, it is written into two parts during the optimization process: the time-containing part βt and the time-excluding part βa. For the time-containing part βt, the time translation average method is used to calculate the minimum root mean square value of its error. For the time-excluding part βa, the Gaussian elimination method is used to calculate the minimum root mean square value of its error. Finally, the two parts are added together to obtain the neural network model determined by the correlation coefficient β matrix. This correlation coefficient matrix is ​​recorded in the memory as a practical energy-saving model; its optimization equation can be expressed as: y = {∏β(1, j)x(1, j)+∏β(2, j)x(1, j)+…}. Through iteration, the optimal β (i = 1, n; j = 1, z) parameter is calculated to minimize Δy. Step 4: The central processing unit outputs a digital control code to the digital analog signal conversion chip (3) to control the current output of the voltage-controlled current source (4); the central processing unit outputs a digital control code to the digital potentiometer (8) to control the voltage output of the voltage-adjustable DC conversion power supply (2); Step 5: The sampling feedback circuit (5) samples the working voltage and working current of the laser diode (9) and feeds them back to the central processing unit; Step 6: The central processing unit adjusts the control code to the digital-to-analog signal conversion chip (3) and the digital potentiometer (8) based on the sampled feedback signal combined with the PID (proportional-integral-differential) algorithm to improve the transient fluctuations in the voltage and current of the laser diode (9).

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