Radio frequency power supply control system and method based on wireless optical communication

Abstract

The invention is applicable to the technical field of radio frequency control of particle accelerators, and provides a radio frequency power supply control system and method based on wireless optical communication, and the method comprises the steps: after high-frequency noise of an analog voltage input signal is suppressed through a low-pass filter, digital processing is completed through analog-to-digital conversion, and a composite light wave signal is generated through coded modulation; driving the LED array to emit modulated light waves; at a radio frequency power supply end, after the driving capability of an output signal is improved through a voltage amplifier, a carrier signal is generated through digital-to-analog conversion and an LC filter; optical signals captured by the photoelectric detector are received, and radio frequency driving signals are reconstructed through digital-to-analog conversion after environmental interference elimination and decoding demodulation are carried out through a trans-impedance amplifier and a band-pass filter. According to the invention, a signal path physical isolation design and a dynamic noise suppression technology are adopted, the problems of common-mode interference, impedance mismatch and signal attenuation existing in traditional cable transmission are effectively solved, and the anti-radiation interference capability and the control precision stability of an accelerator ion source system are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of radio frequency control of particle accelerators, and particularly relates to a radio frequency power supply control system and method based on wireless optical communication. Background Art

[0002] Most of the existing radio frequency power supply control systems rely on traditional optical fiber communication solutions. For example, in ion source or accelerator systems, an electro-optic converter (E / O converter) is usually used to convert an electrical signal into an optical signal, which is transmitted through an optical fiber, and then an optoelectronic converter (O / E converter) is used to convert the optical signal back into an electrical signal for subsequent control and feedback.

[0003] However, with the expansion of the radio frequency power supply system to higher powers, the existing optical fiber communication solutions face greater challenges and need to meet the requirements of precise voltage regulation to control the output of the radio frequency power supply and real-time coordination and communication between multiple power supplies.

[0004] In summary, this application proposes a radio frequency power supply control system and method based on wireless optical communication. Summary of the Invention

[0005] The purpose of the embodiments of the present invention is to provide a radio frequency power supply control system and method based on wireless optical communication, aiming to solve the technical problems existing in the prior art mentioned in the background art.

[0006] The embodiments of the present invention are implemented as follows. A radio frequency power supply control system based on wireless optical communication includes: A control signal source for providing an analog voltage input signal to the ion source control system; A transmitting link analog-to-digital conversion unit for converting the analog voltage input signal into a digital signal; An encoding and modulation unit for decomposing the digital signal into N subcarriers through OFDM modulation and generating a composite modulation waveform after IFFT; A transmitting link digital-to-analog conversion unit for converting the composite modulation waveform into a voltage signal; An LED array for emitting light according to the voltage signal to transmit a visible light signal; An optoelectronic conversion unit for converting the received visible light signal into an electrical signal; A transimpedance amplifier for amplifying the obtained electrical signal to obtain an amplified voltage analog signal; A band-pass filter for filtering the amplified voltage analog signal; A receiving link analog-to-digital conversion unit for converting the amplified voltage analog signal into a digital signal; A demodulation and decoding unit for performing clock recovery and baseband decoding on the digital signal to reconstruct the original digital signal; A receive link digital-to-analog conversion unit for converting an original digital signal into an analog voltage signal as a control drive signal; A voltage amplifier for proportionally amplifying the analog voltage signal through an operational amplifier; A radio frequency power supply for controlling the output power based on the analog voltage signal.

[0007] Preferably, it further includes a low-pass filter for suppressing noise of the analog voltage input signal.

[0008] More preferably, it further includes an LC filter and an optical wave emission driving unit. The LC filter is used to eliminate current ripple caused by dimming; the optical wave emission driving unit is used to convert the composite modulation waveform into a drive current to control the LED array to emit modulated optical waves.

[0009] More preferably, the low-pass filter adopts a Butterworth second-order filtering topology with a cut-off frequency set to 1.2 times the operating frequency band of the radio frequency power supply, for suppressing the interference of high-frequency switching noise on the operation of the receive link analog-to-digital conversion unit.

[0010] More preferably, the LC filter is configured as a seventh-order elliptic function type filter with the center frequency calibrated to the second harmonic position of the fundamental frequency of the radio frequency power supply, for eliminating image noise during the DAC reconstruction process.

[0011] More preferably, the LED array is composed of multiple light-emitting diodes with a wavelength of 850 nm, and the arrangement adopts a 4×4 equally spaced matrix layout, with the adjacent unit spacing greater than 2 times the beam divergence angle, and realizes light intensity superposition and spatial diversity transmission through an independent drive circuit.

[0012] More preferably, the decoding and demodulation unit is built-in with a Viterbi soft decision algorithm, and performs symbol synchronization and error correction on the pulse signal output by the optoelectronic conversion unit through a forward error correction mechanism.

[0013] Another object of the embodiment of the present invention is to provide a radio frequency power supply control method based on wireless optical communication, and the method includes: Obtaining an analog voltage input signal; Converting the analog voltage input signal into a digital signal; Through OFDM modulation, decomposing the digital signal into N subcarriers, and generating a composite modulation waveform after IFFT; Converting the composite modulation waveform into a voltage signal to drive the LED array to send visible light signals; Converting the received visible light signal into an electrical signal; Amplifying the obtained electrical signal and filtering the obtained amplified voltage analog signal; Convert the amplified voltage analog signal into an amplified voltage digital signal; Decode and demodulate the amplified voltage digital signal into a digital voltage signal; Convert the digital voltage signal into an analog voltage signal and output it to the RF power supply.

[0014] Preferably, it further includes the step of equally amplifying the analog voltage signal through a voltage amplifier.

[0015] More preferably, the decoding and demodulation step is completed by decoding the bit information contained in the optical signal based on the waveform information corresponding to the constellation map mapping.

[0016] The beneficial effects of the embodiments of the present invention are as follows: It does not require complex optical fiber wiring. Especially for controlling power supply equipment operating at high voltage potentials, compared with the control system using optical - electrical converters and wired optical fibers, it reduces the installation and maintenance costs, has stronger adaptability. Especially in large - scale experimental platforms, it has better flexibility due to its small space occupancy and compact modules; the transmission link and reception link adopted by the present invention have strong scalability. This system adopts a modular design, can adapt to the increasing demand of the controlled object, the system can be flexibly expanded, which is beneficial to future function expansion and upgrade; the wireless optical communication method used does not need to consider the influence of high - frequency oscillation generated by the RF power supply on the signal, improving the stability of signal transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a specific principle block diagram of a RF power supply control system based on wireless optical communication provided by an embodiment of the present invention; Figure 2 It is a schematic diagram of a voltage amplifier provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0019] It can be understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but unless otherwise specified, these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. For example, without departing from the scope of this application, the first xx script can be called the second xx script, and similarly, the second xx script can be called the first xx script.

[0020] As Figure 1 shown, in one embodiment, a RF power supply control system based on wireless optical communication is proposed, which specifically may include: A control signal source for providing an analog voltage input signal to an ion source control system; A transmitting link analog-to-digital conversion unit for converting the analog voltage input signal into a digital signal; An encoding and modulation unit for decomposing the digital signal into N subcarriers through OFDM modulation and generating a composite modulation waveform after performing IFFT; A transmitting link digital-to-analog conversion unit for converting the composite modulation waveform into a voltage signal; An LED array for emitting light according to the voltage signal to transmit a visible light signal; A photoelectric conversion unit for converting the received visible light signal into an electrical signal; A transimpedance amplifier for amplifying the obtained electrical signal to obtain an amplified voltage analog signal; A band-pass filter for filtering the amplified voltage analog signal; A receiving link analog-to-digital conversion unit for converting the amplified voltage analog signal into a digital signal; A demodulation and decoding unit for performing clock recovery and baseband decoding on the digital signal to reconstruct the original digital signal; A receiving link digital-to-analog conversion unit for converting the original digital signal into an analog voltage signal as a control drive signal; A voltage amplifier for equally amplifying the analog voltage signal through an operational amplifier; A radio frequency power supply for controlling the output power based on the analog voltage signal.

[0021] The radio frequency power supply control system disclosed in the embodiments of the present invention can be generally summarized as a signal transmission link and a signal reception link. Among them, the control signal source, the transmitting link analog-to-digital conversion unit, the encoding and modulation unit, the transmitting link digital-to-analog conversion unit, etc. all belong to the signal transmission link, and the photoelectric conversion unit, the transimpedance amplifier, the band-pass filter, the receiving link analog-to-digital conversion unit, the demodulation and decoding unit, the voltage amplifier, and the radio frequency power supply, etc. all belong to the signal reception link.

[0022] In the actual application of the embodiments of the present invention, the control signal source provides the original signal of the ion source control system and performs impedance matching and spectrum shaping, that is, the aforementioned analog voltage input signal, with a voltage range of 0 - 24V. Of course, the analog voltage input signal can be set and adjusted by the host computer to meet the system requirements. The analog-to-digital conversion unit of the transmission link, namely the ADC in the prior art, is used to convert the analog voltage input signal into a digital signal. Since the accuracy and sampling rate of the ADC are crucial for the final control accuracy of the system, it is necessary to select an ADC with high precision and high sampling rate to process these signals. The digital accuracy of each signal can reach the required accuracy by adjusting the resolution of the ADC (in the embodiments of the present invention, the analog-to-digital conversion unit of the transmission link uses a 16-bit successive approximation ADC to achieve microvolt-level voltage resolution). The digital signal after being converted by the analog-to-digital conversion unit of the transmission link is transmitted to the encoding and modulation unit. The encoding and modulation unit is responsible for processing these digital signals and modulating them through OFDM. After converting the digital signal string output by the analog-to-digital conversion unit of the transmission link, it is decomposed into N subcarriers, and after performing IFFT, a composite modulation waveform is synthesized to ensure the transmission stability and anti-interference ability of the signal. Then, the digital signal is converted into a voltage signal through the digital-to-analog conversion unit of the transmission link as the original voltage signal for driving the LED array, so that the LED array can send an optical signal. The LED array, as a transmitting element, wirelessly transmits the modulated visible light signal to the signal receiving link. The LED array needs to meet a large transmission distance and strong anti-interference ability to ensure that the signal is not interfered and transmitted reliably in a high-voltage environment.

[0023] For the signal receiving link, the optoelectronic conversion unit generally outputs current and voltage as signals for the collected optical signal. The electrically converted signal after optoelectronic conversion is amplified and filtered through a transimpedance amplifier and a band-pass filter. By balancing the noise advantage of a high input impedance and the bandwidth characteristic of a low input impedance, a shunt negative feedback structure of the transimpedance amplifier is adopted to achieve efficient conversion of weak current signals and filter out clutter while maintaining the stability of the transimpedance gain.

[0024] Then, the digital signal after being converted by the analog-to-digital conversion unit of the receiving link is transmitted to the decoding and demodulation unit, and the bit information contained in the optical signal is decoded by mapping the corresponding waveform information through the constellation diagram. Then, the digital voltage signal is converted into a voltage signal through the digital-to-analog conversion unit of the receiving link as the original voltage signal for controlling the radio frequency power supply, and then the original voltage signal is amplified through a voltage amplifier as the control signal for the radio frequency power supply.

[0025] In one case of the embodiments of the present invention, the specific structure of the voltage amplifier is introduced, such as Figure 2As shown, the voltage amplifier serves as the voltage output at the end of the signal receiving link to control the radio frequency power supply. The amplifier used is a through amplifier, and its amplification gain is controlled by the resistance values of Resistor 1, Resistor 2, and Resistor 3 in the feedback circuit. The designed amplification gain is , where G is the amplification gain, and R 1 , R 2 , and R 3 are the resistance values of Resistor 1, Resistor 2, and Resistor 3 respectively. Resistor 4 can be a small resistor, and its gain can be ignored. It is used to prevent overvoltage at the input, thus providing input protection. Resistor 3 serves as a current sampling resistor for output current limiting protection. Inductor 6 functions as an inductive load buffer to suppress transient current surges, and capacitor 8 is used to avoid high-frequency oscillations. The integrated operational amplifier 5 and the compensation resistor are used to adjust the linearity of amplification. OPA445ADDA can be used to form the circuit. Capacitor 11 is used for high-frequency noise filtering at the radio frequency power supply control interface. 7, 9, and 10 in the attached figure are all compensation resistors.

[0026] As Figure 1 shown, as a preferred embodiment of the present invention, it further includes a low-pass filter, and the low-pass filter is used to suppress noise in the analog voltage input signal.

[0027] In the embodiment of the present invention, the low-pass filter is used to suppress noise in the multiple analog voltage input signals provided by the control signal source. Among them, the low-pass filter adopts a Butterworth second-order filter topology, and the cut-off frequency is set to 1.2 times the operating frequency band of the radio frequency power supply, which is used to suppress the interference of high-frequency switching noise on the operation of the analog-to-digital conversion unit in the transmission link.

[0028] As Figure 1 shown, as another preferred embodiment of the present invention, it further includes an LC filter and a light wave emission driving unit. The LC filter is used to eliminate the current ripple caused by dimming; the light wave emission driving unit is used to convert the composite modulation waveform into a driving current to control the LED array to emit modulated light waves. Among them, the LC filter is configured as a seventh-order elliptic function type filter, and the center frequency is calibrated to the second harmonic position of the fundamental frequency of the radio frequency power supply, which is used to eliminate the image noise in the DAC reconstruction process. The light wave emission driving unit serves as the driver of the LED array.

[0029] In one case of the embodiment of the present invention, the LED array is composed of multiple light-emitting diodes with a wavelength of 850 nm, and the arrangement adopts a 4×4 equally spaced matrix layout. The adjacent units are spaced more than twice the beam divergence angle, and the light intensity superposition and spatial diversity transmission are realized through an independent driving circuit.

[0030] As Figure 1As shown, as another preferred embodiment of the present invention, the decoding and demodulation unit incorporates the Viterbi soft decision algorithm to perform symbol synchronization and error correction on the pulse signal output by the optoelectronic conversion unit through a forward error correction mechanism.

[0031] In the embodiment of the present invention, the process of demodulation and decoding is to extract the information in the analog voltage signal obtained by the analog-to-digital conversion unit of the receiving link, perform frequency-domain mapping through FT, and search for the corresponding bit information by matching the constellation diagram.

[0032] In one case of the embodiment of the present invention, the radio frequency power supply further includes: A switch signal setting unit (24V / 0V) for controlling the on / off state of the radio frequency power supply. Preferably, it can be connected to the signal receiving link through a DB15 interface to control the on / off of the radio frequency power supply; A power setting unit (0-10V) for setting the power output of the radio frequency power supply. For example, the power output of the radio frequency power supply can be controlled through a voltage setting signal, connected to the signal receiving link through a DB15 interface to control the power setting pin of the radio frequency power supply, and set the output power range of the radio frequency power supply. Among them, a 0-10V voltage setting signal corresponds to the zero to full-scale power output of the radio frequency power supply; A positive power feedback unit for monitoring the forward power output of the radio frequency power supply; A negative power feedback unit for monitoring the reverse power output of the radio frequency power supply.

[0033] The embodiment of the present invention also provides a radio frequency power supply control method based on wireless optical communication. The method includes the following steps: Step S1, obtain an analog voltage input signal; Step S2, convert the analog voltage input signal into a digital signal; Step S3, through OFDM modulation, decompose the digital signal into N subcarriers, and generate a composite modulation waveform after IFFT; Step S4, convert the composite modulation waveform into a voltage signal to drive the LED array to send visible light signals; Step S5, convert the received visible light signal into an electrical signal; Step S6, amplify the obtained electrical signal and filter the obtained amplified voltage analog signal; Step S7, convert the amplified voltage analog signal into an amplified voltage digital signal; Step S8, decode and demodulate the amplified voltage digital signal into a digital voltage signal; Step S9, convert the digital voltage signal into an analog voltage signal and output it to the radio frequency power supply.

[0034] Among them, in step S5, the received visible light signal is converted into an electrical signal, which can be achieved by an avalanche photodiode APD, a photomultiplier tube PMT, and a silicon photocell PIN. The embodiments of the present invention do not make specific limitations.

[0035] In the embodiments of the present invention, the voltage range of the analog voltage input signal is 0 - 24V. Of course, the analog voltage input signal can be set and adjusted by the host computer to meet the system requirements. The digital signal after being converted by the analog-to-digital conversion unit of the transmitting link is transmitted to the encoding and modulation unit. The encoding and modulation unit is responsible for processing these digital signals, modulating them through OFDM, converting the digital signal string output by the analog-to-digital conversion unit of the transmitting link, decomposing it into N subcarriers, performing IFFT, and then synthesizing a composite modulation waveform to ensure the transmission stability and anti-interference ability of the signal. Then, the digital signal is converted into a voltage signal through the digital-to-analog conversion unit of the transmitting link as the original voltage signal for driving the LED array, so that the LED array can send out optical signals.

[0036] The photoelectric conversion unit generally outputs current and voltage as signals for the collected optical signal. The electrical signal after photoelectric conversion is amplified and filtered through a transimpedance amplifier and a band-pass filter. By balancing the noise advantage of a high input impedance and the bandwidth characteristic of a low input impedance, a shunt negative feedback structure of the transimpedance amplifier is adopted to achieve efficient conversion of weak current signals and filter out clutter while maintaining the stability of the transimpedance gain.

[0037] Then, the digital signal after being converted by the analog-to-digital conversion unit of the receiving link is transmitted to the decoding and demodulation unit, and the bit information contained in the optical signal is decoded by mapping the corresponding waveform information through the constellation diagram. Then, the digital voltage signal is converted into a voltage signal through the digital-to-analog conversion unit of the receiving link as the original voltage signal for controlling the radio frequency power supply.

[0038] In the embodiments of the present invention, since the digital signal after demodulation and decoding is transmitted to the digital-to-analog conversion unit of the receiving link, the digital-to-analog conversion unit of the receiving link converts it into an analog voltage signal. The output range of the analog voltage signal is 0 - 10V, and the control signal of the radio frequency power supply is 0 - 24V. Therefore, it is necessary to perform proportional amplification on it using a voltage amplifier and then use it as the control signal of the radio frequency power supply.

[0039] Therefore, in the embodiments of the present invention, it further includes the step of performing proportional amplification on the analog voltage signal through a voltage amplifier.

[0040] As can be seen from the above embodiments, the wireless communication technology used in the technical solution of the present invention does not require complex optical fiber wiring. Especially when controlling power supply equipment operating at high voltage potentials, compared with the control system using optical - electrical converters and wired optical fibers, it reduces the installation and maintenance costs, has stronger adaptability. Especially in large - scale experimental platforms, it has better flexibility due to its small space occupancy and compact modules; the transmit link and receive link adopted by the present invention have strong scalability. The system adopts a modular design, can adapt to the increasing requirements of the controlled object, and the system can be flexibly expanded, which is beneficial to future function expansion and upgrade; the wireless optical communication method used does not need to consider the influence of high - frequency oscillation generated by the radio - frequency power supply on the signal, improving the stability of signal transmission.

[0041] The technical features of the above - mentioned embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above - mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0042] The above - mentioned embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it cannot be understood as a limitation to the scope of the invention patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent of the present invention should be subject to the appended claims.

[0043] The above is only the preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A radio frequency power supply control system based on wireless optical communication, characterized in that: include: A control signal source, used for providing an analog voltage input signal for an ion source control system; A transmitting link analog-to-digital conversion unit, used to convert an analog voltage input signal into a digital signal; The coding and modulation unit is used to decompose the digital signal into N subcarriers through OFDM modulation, and generate a composite modulation waveform after IFFT; A transmitting link digital-to-analog conversion unit, used to convert a composite modulated waveform into a voltage signal; An LED array, configured to emit light according to a voltage signal to transmit a visible light signal; A photoelectric conversion unit, used for converting the received visible light signal into an electrical signal; A transimpedance amplifier is used to amplify the obtained electrical signal to obtain an amplified voltage analog signal; A bandpass filter for filtering the amplified voltage analog signal; A receiving link analog-to-digital conversion unit, used to convert the amplified voltage analog signal into a digital signal; The demodulation and decoding unit is used to perform clock recovery and baseband decoding on the digital signal to reconstruct the original digital signal; A receiving link digital-to-analog conversion unit, used to convert the original digital signal into an analog voltage signal as a control drive signal; A voltage amplifier is used to amplify the analog voltage signal proportionally through an operational amplifier; A radio frequency power supply is used to control output power based on an analog voltage signal.

2. The system according to claim 1, characterized in that A low-pass filter is also included, and the low-pass filter is used to suppress noise on the analog voltage input signal.

3. The system according to claim 1, characterized in that It also includes an LC filter and a light wave emission driving unit. The LC filter is used to eliminate the current ripple caused by dimming; the light wave emission driving unit is used to convert the composite modulated waveform into a driving current to control the LED array to emit modulated light waves.

4. The system according to claim 2, characterized in that The low-pass filter adopts a Butterworth second-order filter topology, and the cut-off frequency is set to 1.2 times the operating frequency band of the RF power supply, so as to suppress the interference of high-frequency switching noise on the operation of the transmission link analog-to-digital conversion unit.

5. The system according to claim 3, characterized in that The LC filter is configured as a seventh-order elliptic function filter, and the center frequency is calibrated to the second harmonic position of the radio frequency power supply fundamental frequency, so as to eliminate the image noise in the DAC reconstruction process.

6. The system according to claim 1 or 2 or 3 or 4 or 5, characterized in that: The LED array is composed of multiple 850nm wavelength light emitting diodes, arranged in a 4×4 equidistant matrix layout, with the interval between adjacent units being greater than twice the beam divergence angle, and light intensity superposition and spatial diversity transmission are achieved through an independent driving circuit.

7. The system according to claim 1, characterized in that The decoding and demodulation unit has a built-in Viterbi soft decision algorithm, and performs symbol synchronization and error correction on the pulse signal output by the photoelectric conversion unit through a forward error correction mechanism.

8. A radio frequency power supply control method based on wireless optical communication, characterized in that: The method comprises: Get analog voltage input signal; Convert analog voltage input signals into digital signals; Through OFDM modulation, the digital signal is decomposed into N subcarriers, and a composite modulated waveform is generated after IFFT; Convert the composite modulated waveform into a voltage signal to drive the LED array to send a visible light signal; Convert the received visible light signal into an electrical signal; amplifying the obtained electrical signal, and filtering the obtained amplified voltage analog signal; Converting the amplified voltage analog signal into an amplified voltage digital signal; Decoding and demodulating the amplified voltage digital signal into a digital voltage signal; The digital voltage signal is converted into an analog voltage signal and then output to the RF power supply.

9. The method according to claim 8, characterized in that The method also includes the step of proportionally amplifying the analog voltage signal through a voltage amplifier.

10. The method according to claim 8, characterized in that The decoding and demodulation step is completed by decoding the bit information contained in the optical signal based on the waveform information corresponding to the constellation diagram mapping.

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