Temperature control device and method for mirror compensation

Abstract

The application discloses a temperature control device and method for mirror compensation, and relates to the technical field of laser equipment. The device comprises a power module, N heating modules, M temperature probes, N switch control modules, a substation control module and a main station control module. The main station control module is configured to: when the current temperature of a target heating module does not reach a target temperature, and the current temperatures of the M temperature probes are all within a preset temperature threshold range, in response to receiving a mirror compensation signal of a host computer, determining a target duty ratio and a target frequency corresponding to the target heating module. Based on the target duty ratio and the target frequency, a corresponding pulse control signal is directly output or output through the substation control module to the corresponding switch control module. The application compensates the thermal deformation of the mirror through the temperature compensation method, and has a simple structure and high regulation and control precision.

Description

Technical Field

[0001] This application relates to the field of laser equipment technology, and in particular to a temperature control device and method for mirror compensation. Background Technology

[0002] The beamline deflector box is a key vacuum component at the front end or middle section of a laser beamline station. Its core function is to deflect X-rays or extreme ultraviolet light from the light source using precision mirrors in an ultra-high vacuum environment, thereby achieving optical path switching, harmonic suppression, and beam shaping.

[0003] However, under irradiation by high-repetition-rate free-electron lasers, the deflection mirrors of the beamline deflection box experience enormous thermal loads, leading to thermal deformation of the mirrors. This minute mirror deformation directly causes wavefront distortion, severely reducing the X-ray beam quality and becoming a key bottleneck restricting the performance of laser equipment. Summary of the Invention

[0004] The main objective of this application is to provide a temperature control device for mirror compensation, which aims to solve the problem of beam quality degradation caused by thermal deformation of the deflector in a high repetition frequency free electron laser environment.

[0005] To achieve the above objectives, the temperature control device for mirror compensation proposed in this application includes: Power module; N heating modules are used to heat the area of ​​the mirror to be compensated. M temperature probes are connected to the power module to detect the temperature of N heating modules and output M temperature detection signals, where M ≤ N; N switch control modules are respectively connected to the corresponding heating module and the power module, and are used to control the working status of the N heating modules; The substation control module is connected to the power supply module and the K switch control modules respectively; The main station control module is connected to M temperature probes, the substation control module, and I switch control modules, and is used to connect to the host computer; I=NK; The main station control module is configured as follows: In response to receiving a temperature threshold setting signal from the host computer, the preset temperature threshold range of the M temperature probes is determined; In response to receiving the target temperature signal from the host computer, the target temperature corresponding to the target heating module is determined; Based on the M temperature detection signals, determine the current temperature of the M temperature probes; Based on the current temperatures of the M temperature probes and the distribution positions of the N heating modules and the M temperature probes, determine the current temperature of the target heating module; When the current temperature of the target heating module has not reached the target temperature, and the current temperatures of the M temperature probes are all within the preset temperature threshold range, the target duty cycle and target frequency corresponding to the target heating module are determined in response to the mirror compensation signal received from the host computer. Based on the target duty cycle and the target frequency, a corresponding pulse control signal is output to the corresponding switch control module, or the target duty cycle and the target frequency are sent to the substation control module to control the substation control module to output a corresponding pulse control signal to the corresponding switch control module.

[0006] In one embodiment, prior to receiving the mirror compensation signal from the host computer, the master station control module is further configured to: In response to receiving a first power signal from the host computer, the difference between the actual beam emission power and the preset beam emission power in the specular illumination area is calculated; the first power signal represents the preset beam emission power. When the current temperature of the target heating module has not reached the target temperature, and the current temperatures of the M temperature probes are within the preset temperature threshold range, and the difference does not exceed the preset power error range, the received mirror compensation signal is responded to. The response to the received mirror compensation signal is prohibited when at least one of the following conditions is met: the current temperature of the target heating module reaches the target temperature; the current temperature of any of the temperature probes is outside the preset temperature threshold range; and the difference exceeds the preset power error range.

[0007] In one embodiment, the substation control module includes: An Ethernet communication unit is connected to the main station control module via Ethernet. J pulse output units, each pulse output unit is connected to 2 of the switch control modules respectively; the J pulse output units are used to generate corresponding pulse control signals and send them to the corresponding switch control modules according to the target duty cycle and target frequency of the target heating module received by the substation control module; J is a positive integer greater than or equal to 1 / 2.

[0008] In one embodiment, N is an even number between 16 and 32, I is 4 or 8, and J = N / 2 - I / 2.

[0009] In one embodiment, the switch control module includes a solid-state relay, the controlled terminal of which is connected to the corresponding master station control module or the pulse output unit, the first terminal of which is connected to the power supply module, and the second terminal of which is connected to the corresponding heating module.

[0010] In one embodiment, the preset power error range is an adjustable parameter; the master station control module is further configured to: In response to receiving a power threshold setting signal from the host computer, the preset power error range is determined.

[0011] In one embodiment, the master station control module has a communication interface, and the master station control module is connected to the host computer through the communication interface; the communication interface uses a preset industrial communication protocol for data interaction. The memory of the master station control module is equipped with an address mapping table, which stores the mapping relationship between process variable addresses and communication data addresses defined by the preset industrial communication protocol; the process variable addresses include at least one of the following: a first variable address corresponding to the temperature threshold setting signal, a second variable address corresponding to the target temperature signal, a third variable address corresponding to the mirror compensation signal, and a fourth variable address corresponding to the power threshold setting signal; The master station control module is further configured to: in response to a read / write request received from the host computer via the communication interface, perform read / write operations on the corresponding first variable address, second variable address, third variable address, and fourth variable address based on the address mapping table.

[0012] In one embodiment, the preset industrial communication protocol includes at least one of the S7nodave protocol, Modbus-TCP protocol, and OPC UA protocol.

[0013] In one embodiment, the master station control module is also used to feed back at least one of the following status parameters through the communication interface: power failure status, parameter loading error status, duty cycle setting invalid status, frequency setting invalid status, and pulse output enable status.

[0014] This application also proposes a temperature control method for mirror compensation, applied to the mirror compensation temperature control device described above; the mirror compensation temperature control method includes: In response to receiving a temperature threshold setting signal from the host computer, the preset temperature threshold range of the M temperature probes is determined; In response to receiving the target temperature signal from the host computer, the target temperature corresponding to the target heating module is determined; Based on the M temperature detection signals, determine the current temperature of the M temperature probes; Based on the current temperatures of the M temperature probes and the distribution positions of the N heating modules and the M temperature probes, determine the current temperature of the target heating module; When the current temperature of the target heating module has not reached the target temperature, and the current temperatures of the M temperature probes are all within the preset temperature threshold range, the target duty cycle and target frequency corresponding to the target heating module are determined in response to the mirror compensation signal received from the host computer. Based on the target duty cycle and the target frequency, a corresponding pulse control signal is output to the corresponding switch control module, or the target duty cycle and the target frequency are sent to the substation control module to control the substation control module to output a corresponding pulse control signal to the corresponding switch control module.

[0015] This application's technical solution employs a temperature control device for mirror compensation, including a power supply module, N heating modules, M temperature probes, N switch control modules, a substation control module, and a main station control module. The main station control module is configured to: Step S10, in response to receiving a temperature threshold setting signal from the host computer, determine the preset temperature threshold range for the M temperature probes. Step S20, in response to receiving a target temperature signal from the host computer, determine the target temperature corresponding to each heating module. Step S30, based on the M temperature detection signals, determine the current temperature of the M temperature probes. Step S40, based on the current temperatures of the M temperature probes and the distribution positions of the N heating modules and the M temperature probes, determine the current temperature of the target heating module. Step S50, when the current temperature of the target heating module has not reached the target temperature, and the current temperatures of all M temperature probes are within the preset temperature threshold range, in response to receiving a mirror compensation signal from the host computer, determine the target duty cycle and target frequency corresponding to the target heating module. In step S60, based on the target duty cycle and target frequency, a corresponding pulse control signal is output to the corresponding switch control module, or the target duty cycle and target frequency are sent to the substation control module to control the substation control module to output the corresponding pulse control signal to the corresponding switch control module. Thus, this application, while ensuring multi-channel large-scale compensation capability, compensates for the thermal deformation of the deflector in a high-repetition-frequency free-electron laser environment through temperature compensation, and achieves high precision in compensation control for different regions of the mirror surface, effectively improving beam pointing stability and wavefront quality. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 A schematic diagram of an embodiment of the temperature control device provided in this application; Figure 2 A schematic diagram of another embodiment of the temperature control device provided in this application; Figure 3 A schematic flowchart of an embodiment of the temperature control method provided in this application; Figure 4 This is a flowchart illustrating another embodiment of the temperature control method provided in this application.

[0018] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0021] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0022] The beamline deflector box is a key vacuum component at the front end or mid-section of a laser beamline station. Its core function is to deflect X-rays or extreme ultraviolet light from the light source using precision mirrors in an ultra-high vacuum environment, thereby achieving optical path switching, harmonic suppression, and beam shaping. However, under the irradiation of high-repetition-rate free-electron lasers, the deflecting mirrors of the beamline deflector box experience enormous thermal loads, inducing thermal deformation. This minute mirror deformation directly leads to wavefront distortion, severely reducing the X-ray beam quality and becoming a critical bottleneck restricting the performance of laser equipment.

[0023] This application proposes a temperature control device for mirror compensation.

[0024] Please see Figure 1 In the first embodiment of this application, the temperature control device for mirror compensation includes: Power module; N heating modules are used to heat the area of ​​the mirror to be compensated. M temperature probes are connected to the power module to detect the temperature of N heating modules and output M temperature detection signals, where M≤N; N switch control modules are connected to the corresponding heating modules and power modules respectively, and are used to control the working status of the N heating modules; The substation control module is connected to the power supply module and K switch control modules respectively; The main station control module connects to M temperature probes, substation control modules, and I switch control modules, and is used to connect to the host computer, where I=NK; Please see Figure 3 The main station control module is configured to execute steps S10~S60: Step S10: In response to receiving the temperature threshold setting signal from the host computer, determine the preset temperature threshold range for the M temperature probes.

[0025] Step S20: In response to receiving the target temperature signal from the host computer, determine the target temperature corresponding to each heating module.

[0026] Step S30: Determine the current temperature of the M temperature probes based on the M temperature detection signals.

[0027] Step S40: Determine the current temperature of the target heating module based on the current temperatures of the M temperature probes and the distribution positions of the N heating modules and the M temperature probes.

[0028] Step S50: When the current temperature of the target heating module has not reached the target temperature, and the current temperatures of the M temperature probes are all within the preset temperature threshold range, in response to receiving the mirror compensation signal from the host computer, the target duty cycle and target frequency corresponding to the target heating module are determined.

[0029] Step S60: Based on the target duty cycle and target frequency, output the corresponding pulse control signal to the corresponding switch control module, or send the target duty cycle and target frequency to the substation control module to control the substation control module to output the corresponding pulse control signal to the corresponding switch control module.

[0030] It should be noted that the temperature gradient of the mirror surface can cause the mirror surface shape distortion. In this embodiment, an adjustable heat source is introduced to compensate for the non-uniform heat load of the mirror surface. The spatially addressable temperature compensation method can achieve sub-nanometer-level surface shape control under medium and high power X-ray beam irradiation.

[0031] It should be noted that the preset temperature threshold range refers to the effective temperature measurement window pre-configured and issued by the host computer based on the rated operating range of the temperature probe and the safe tolerance temperature of the mirror material. The lower limit of this range is used to eliminate the risk of sensor nonlinearity error or condensation in low-temperature environments, while the upper limit is used to prevent permanent damage to the probe or measurement drift due to overheating. In the actual execution process, the main station control module compares and verifies the current temperature of each of the M temperature probes collected in real time with the preset temperature threshold range. If the current temperature of any temperature probe exceeds this range, it indicates that there may be a fault in the temperature measurement link or that it is in an unsafe operating area. At this time, even if a mirror compensation signal is received, subsequent pulse generation and heating actions will be prohibited, thereby avoiding overcompensation, undercompensation, or device damage caused by erroneous temperature feedback. Only when the current temperature of all temperature probes is stably within the preset temperature threshold range is the temperature measurement data considered reliable and the hardware status considered safe, thus allowing the response to the mirror compensation signal and entry into the heating control process.

[0032] M temperature detection signals can be the raw voltage signals acquired by the main station control module through M analog signal acquisition channels; the distribution position refers to the spatial topological correspondence matrix between the heating modules and temperature probes on the mirror surface. When M < N, taking M=8 and N=20 as an example, after the main station control module reads the 8 channels of analog input and converts the electrical signals into physical temperature values, it uses the values ​​of the 8 discrete temperature measurement points to calculate the current temperature field distribution of the 20 heating modules based on the pre-stored spatial mapping algorithm. Specifically, assuming that the 8 temperature probes are uniformly distributed in a ring on the inner circle of the mirror surface, and the 20 heating modules are distributed in a double-ring array across the full diameter of the mirror surface, the main station control module first constructs a spatial mapping matrix containing 20×8 weighting coefficients based on the radial distance and angular offset between each temperature probe and the adjacent heating module; then, it multiplies the column vector of the 8 measured temperature values ​​with the spatial mapping matrix, and calculates the current temperature value corresponding to each of the 20 heating modules through weighted interpolation. When M=N, the temperature probes are configured in a one-to-one correspondence with the heating modules, and the current temperature of the heating modules can be directly obtained from the temperature detection signals output by the temperature probes. It should be noted that I is a positive integer greater than or equal to 4, K is a positive integer greater than or equal to 2, N is a positive integer greater than or equal to 6, and M is a positive integer less than or equal to N.

[0033] The mirror compensation signal refers to a composite control command calculated by the host computer based on the thermal compensation algorithm corresponding to the actual mirror box. This command includes the target duty cycle and target frequency for each target heating module. It represents the heating strategy required to correct mirror thermal distortion under the current operating conditions. The thermal compensation algorithm is a reverse-engineered model in the host computer used to correct mirror thermal distortion. Based on real-time monitoring or prediction of mirror surface shape errors, combined with the thermal influence functions of each heating module and system constraints, it optimizes and calculates the optimal heating strategy required to offset the current distortion. This strategy is then transformed into a composite control command containing the target duty cycle and frequency to actively apply controlled thermal deformation to accurately offset harmful thermal distortion and maintain optical surface shape accuracy. The main station control module can parse the received mirror compensation signal to determine multiple target duty cycles and multiple target frequencies corresponding to multiple target heating modules. The target duty cycle determines the proportion of the switching control module's conduction time within a switching cycle, used to control the average output intensity of the heating power. The target frequency determines the duration of this cycle, i.e., the speed of the switching action per unit time, affecting the smoothness of the heating response and the amplitude of temperature fluctuations. By adjusting the combination of these two parameters, the main station control module can execute different heating strategies for each target heating module to heat the module to the target temperature, achieving precise temperature control of different areas of the mirror and ensuring stable beam quality of the optical system.

[0034] Please see Figure 2 In one embodiment, the substation control module includes: The Ethernet communication unit connects to the main station control module via Ethernet. There are J pulse output units, each of which is connected to two switch control modules. The J pulse output units are used to generate corresponding pulse control signals and send them to the corresponding switch control modules based on the target duty cycle and target frequency of the target heating module received by the substation control module. J is a positive integer greater than or equal to 1 / 2.

[0035] It should be noted that N can be an even number between 16 and 32, I can be 4 or 8, and J = N / 2 - I / 2. M can be set to 20 or 8.

[0036] It should be noted that the switch control module includes a solid-state relay. The controlled terminal of the solid-state relay is connected to the corresponding master station control module or pulse output unit. The first terminal of the solid-state relay is connected to the power supply module, and the second terminal is connected to the corresponding heating module. The heating module can use a heating resistor for heating. The heating resistor is placed in the non-illuminated area of ​​the deflector in the mirror box. Controlling the temperature of the heating resistor can affect the thermal balance of the deflector surface, thereby reducing the beam quality affected by the deformation of the deflector.

[0037] In this embodiment, the pulse control signal uses PWM modulation to maintain a constant temperature of the heating resistor. Given a fixed duty cycle (i.e., a constant average output power), the output frequency directly determines the thermal balance stability of the resistor: at low frequencies (e.g., 1Hz), the heating and cooling cycles are long, leading to significant temperature fluctuations. Increasing the frequency (e.g., 10Hz, 100Hz, or even 1000Hz) can effectively shorten the heat accumulation and dissipation amplitude within a single on / off cycle, making temperature changes smoother. Therefore, to suppress thermal shock and improve temperature control accuracy, this embodiment uses a solid-state relay (model DR2220D20U) as the switching device. It supports a 1000Hz PWM modulation frequency and employs an integrated heat dissipation structure to ensure long-term reliability under high-frequency switching. It can quickly and accurately follow the high-frequency PWM control signal for on / off switching, thereby ensuring the thermal balance stability of the heating resistor under high repetition frequency conditions, ultimately achieving the precise temperature control required for nanometer-level mirror compensation.

[0038] Taking a specific implementation configuration with N, M, I, and J of 20, 8, 4, and 8 respectively as an example: The main station control module uses an S7-1500 compact programmable logic controller (CPU1511C), which natively supports 4 channels of 100kHz high-speed pulse output (minimum pulse width 2μs) and integrates an 8-channel analog acquisition module for real-time acquisition of temperature signals from 8 temperature probes. The Ethernet communication unit of the substation control module uses an ET200SP PROFINET interface module (IM 155-6PN ST) to achieve real-time communication with the main station; the pulse output unit includes 8 high-speed pulse process modules (TM Pulse 2×24V), each module having 2 independent 100kHz pulse output channels (minimum pulse width 1μs), providing a total of 16 channels of PWM pulse signals with adjustable duty cycle and frequency, which, together with the main station's native 4 pulse channels, cover the driving requirements of all 20 heating channels. The switching control module uses a DR2220D20U solid-state relay, supporting a 1000Hz PWM modulation frequency and employing an integrated heat dissipation structure to ensure long-term reliability under high-frequency switching. The power supply module has two independent power supplies: the first power supply module uses DC12V / 10A, dedicated to powering 20 heating modules, 8 temperature probes, and 20 solid-state relays; the second power supply module uses DC24V / 10A, powering the main station CPU1511C, the substation IM 155-6PN ST, and 8 TM Pulse modules, achieving electrical isolation between the power circuit and the control circuit. In addition, the device is equipped with quick-connect terminal blocks as standardized interfaces for external heating resistors, and a five-port network switch to provide Ethernet access ports for the host computer and other external devices, thus forming a complete, compact, and rapidly deployable mirror-compensated temperature control device. In this embodiment, the power supply module can be equipped with robust and reliable aviation connectors, effectively reducing the risk of accidental damage during handling and transportation, while a dedicated power-on key interface ensures system operational safety. The external network interface connects directly to the internal switch of the device for communication with the host computer. Users do not need to open the cabinet or concern themselves with the internal structure of the device; simply powering it on and establishing communication connections is sufficient for operation, significantly reducing the learning curve. The duty cycle of the PWM pulse signals of the main station CPU1511C and the substation IM 155-6PN ST has an adjustable resolution of no less than 1 / 27648, ensuring that each heating output can independently and stably execute temperature fine-tuning commands. With 20 parallel outputs, this provides differentiated and high-precision thermal compensation for different positions on the mirror surface.

[0039] This embodiment aims to propose a highly reliable, high-precision, and flexible mirror thermal compensation temperature control device to solve the beam quality degradation problem caused by thermal deformation of the deflector in a high-repetition-frequency free-electron laser environment. In this embodiment, the device adopts a master-station and sub-station collaborative control architecture. The master-station control module is directly connected to M temperature probes and directly drives I switch control modules. The sub-station control modules share the driving tasks of the remaining K switch control modules (I=NK), collectively forming N independent temperature control loops. The master-station control module is configured as follows: Step S10, in response to receiving a temperature threshold setting signal from the host computer, determines the preset temperature threshold range for the M temperature probes. Step S20, in response to receiving a target temperature signal from the host computer, determines the target temperature corresponding to each heating module. Step S30, based on the M temperature detection signals, determines the current temperature of the M temperature probes. Step S40, based on the current temperatures of the M temperature probes and the distribution positions of the N heating modules and the M temperature probes, determines the current temperature of the target heating module. Step S50: When the current temperature of the target heating module has not reached the target temperature, and the current temperatures of all M temperature probes are within the preset temperature threshold range, in response to the received mirror compensation signal from the host computer, the target duty cycle and target frequency corresponding to the target heating module are determined. Step S60: Based on the target duty cycle and target frequency, a corresponding pulse control signal is output to the corresponding switch control module, or the target duty cycle and target frequency are sent to the substation control module to control the substation control module to output the corresponding pulse control signal to the corresponding switch control module. Thus, this embodiment introduces a dual safety interlock mechanism. The mirror compensation signal is only responded to and the corresponding target duty cycle and target frequency are generated when the current temperature of the target heating module has not reached the target temperature and the temperatures of all probes are within the preset safety threshold range, effectively avoiding the risk of miscompensation caused by sensor malfunction or overheating. Furthermore, when the target heating module corresponds to the native heating channel of the main station control module, the main station control module directly calls the internal high-speed timer resources to generate the corresponding pulse control signal according to the target duty cycle and target frequency, and sends it directly to the corresponding switch control module for control through the native high-speed pulse output channel. When the target heating module corresponds to the extended heating channel of the substation control module, the main station control module sends the target duty cycle and target frequency to the substation control module, which independently generates the pulse control signal and drives the corresponding switch control module. Compared with the prior art, this embodiment solves the technical problem that the number of native high-speed pulse channels in the temperature control device is limited and cannot meet the needs of large-scale multi-channel mirror compensation heating, avoids the cost surge caused by replacing with a higher-specification expensive controller, and significantly simplifies the system structure and wiring complexity with a low-cost expansion method.Furthermore, by combining independently adjustable duty cycle and frequency parameters, each heating module can perform fine and differentiated temperature compensation based on the degree of local deformation of the mirror, avoiding local over-compensation or under-compensation. While ensuring the large-scale compensation capability of multiple channels, it solves the problem of beam quality degradation caused by thermal deformation of the deflector in high repetition frequency free electron laser environment, effectively improving beam pointing stability and wavefront quality.

[0040] Please see Figure 1 and Figure 4 Based on the first embodiment, in the second embodiment of this application, before receiving the mirror compensation signal from the host computer, the main station control module is further configured to execute steps S5001~S5003: Step S5001: In response to receiving the first power signal from the host computer, calculate the difference between the actual beam emission power and the preset beam emission power in the specular illumination area; the first power signal represents the preset beam emission power. Step S5002: When the current temperature of the target heating module has not reached the target temperature, and the current temperatures of the M temperature probes are all within the preset temperature threshold range, and the difference does not exceed the preset power error range, respond to the received mirror compensation signal. Step S5003: When at least one of the following conditions is met, the current temperature of the target heating module reaches the target temperature, the current temperature of any temperature probe is outside the preset temperature threshold range, and the difference exceeds the preset power error range, the response to the received mirror compensation signal is prohibited.

[0041] It should be noted that the first power signal refers to the command data issued by the host computer based on the optical system theoretical model, characterizing the preset beam emission power of the illuminated area of ​​the mirror. The actual beam emission power is the current real output power collected by the sensors configured on the mirror housing itself. After receiving the first power signal from the host computer, the main station control module parses it into the preset beam emission power value and simultaneously obtains the current actual beam emission power, calculating the difference between the two through subtraction.

[0042] Before responding to the mirror compensation signal, this embodiment implements a dual optical and thermal safety verification mechanism through the main station control module: First, it analyzes the first power signal issued by the host computer based on the optical theoretical model to obtain the preset beam emission power, and simultaneously collects the actual beam emission power fed back by the mirror box sensor. The power difference is obtained through subtraction. Then, this difference is used in conjunction with temperature conditions for judgment. Only when all three conditions are met simultaneously—the current temperature of the heating module has not reached the target temperature, the temperatures of all M probes are within the preset temperature threshold range, and the power difference does not exceed the preset power error range—is the mirror compensation signal allowed to be responded to and heating control initiated. If any condition is not met, the response is immediately prohibited. This embodiment incorporates the beam power index into the safety interlock system to avoid miscompensation when power errors occur, thus preventing secondary mirror distortion caused by miscompensation.

[0043] It should be noted that during the output of the corresponding pulse control signal, if at least one of the following conditions is met: the current temperature of the target heating module reaches the target temperature, the current temperature of any temperature probe is outside the preset temperature threshold range, and the difference exceeds the preset power error range, the control will stop outputting the pulse control signal.

[0044] In one embodiment, the preset power error range is an adjustable parameter; before step S5002, the master station control module is also configured to execute step S5000: In response to receiving the power threshold setting signal from the host computer, the preset power error range is determined.

[0045] In this embodiment, the host computer can dynamically set the preset power error range, enabling the main station control module to flexibly adjust the error accuracy according to different operating conditions, thereby improving the flexibility of control.

[0046] Based on the second embodiment, in the third embodiment of this application, the master station control module has a communication interface, and the master station control module is connected to the host computer through the communication interface; the communication interface uses a preset industrial communication protocol for data interaction. The main station control module's memory contains an address mapping table, which stores the mapping relationship between process variable addresses and communication data addresses defined by a preset industrial communication protocol. The process variable addresses include at least one of the following: a first variable address corresponding to the temperature threshold setting signal, a second variable address corresponding to the target temperature signal, a third variable address corresponding to the mirror compensation signal, and a fourth variable address corresponding to the power threshold setting signal. The master station control module is also configured to: respond to read / write requests received from the host computer via the communication interface, and perform read / write operations on the corresponding first variable address, second variable address, third variable address and fourth variable address based on the address mapping table.

[0047] It should be noted that the address mapping table is an index structure stored in the main station control module's memory, which maps internal process variable addresses to communication data addresses defined by a preset industrial communication protocol. During execution, the main station control module receives read / write requests from the host computer via the communication interface, quickly locates the addresses of the first to fourth variables based on the address mapping table, and completes the reading and writing of preset temperature threshold ranges, target temperatures, target duty cycles and frequencies, and preset power error ranges. Thus, this implementation method achieves remote dynamic configuration of key thermal compensation parameters, improving the device's adaptability to operating conditions and the flexibility of engineering deployment.

[0048] It should be noted that the default industrial communication protocols include at least one of the following: S7nodave protocol, Modbus-TCP protocol, and OPC UA protocol.

[0049] In this implementation, it is supported that one or a combination of three preset industrial communication protocols can be flexibly selected according to specific needs in practical applications. Among them, the S7nodave protocol is an open-source communication library based on low-level memory access, which can achieve low-latency direct data connection without writing additional programs on the PLC side; the Modbus-TCP protocol is a Modbus protocol encapsulated in Ethernet, which is suitable for simple cross-platform data acquisition and device networking due to its high versatility and low configuration cost; and the OPCUA protocol, as a new generation of industrial IoT international standard, has a built-in powerful data semantic model and high-level security mechanism, which can realize complex data interaction across platforms and vendors.

[0050] In another embodiment, the master station control module is also used to feed back at least one of the following status parameters through the communication interface: power failure status, parameter loading error status, duty cycle setting invalid status, frequency setting invalid status, and pulse output enable status.

[0051] It should be noted that status parameters refer to the set of diagnostic information generated in real time by the master station control module during operation, characterizing its own health status and the validity of control commands. Specifically, these include power failure status, parameter loading error status, invalid duty cycle setting status, invalid frequency setting status, and pulse output enable status. During execution, the master station control module continuously performs self-checks on these five types of statuses and feeds back to the host computer via a preset industrial communication protocol through the communication interface. This allows the host computer to monitor the integrity of the master station's operation and the legality of command execution in real time. This enhances the fault observability and operational safety of the temperature control device.

[0052] Based on the first to third embodiments, the specific working principle in an exemplary embodiment of this application is explained as follows: In this embodiment, the host computer runs on an Ubuntu 24.04.03 LTS Linux system and is equipped with the EPICS Base software package. It establishes a connection with the temperature control device through the S7nodave-3.0.2 industrial communication protocol. To enhance the reusability of process variables (PVs) and reduce redundant coding, the host computer's IOC (Input / Output Configuration) uses address-encapsulated variable types to directly read and write the encapsulated address space, which is then mapped to the physical output address by the master station control module. The master station control module interacts with the pulse output unit through the Ethernet communication unit, providing a total of 20 PWM control channels (4 channels for the master station control module and 16 channels for the slave station control module), which operate on the solid-state relay control side. The solid-state relay output side is connected to a DC 12V / 10A power supply and terminal block, providing independent power drive for the heating resistors in each area. At the same time, the master station provides 8 temperature monitoring interfaces for the host computer, supporting the setting of minimum / maximum thresholds (default 20℃~40℃) and reading real-time temperature feedback for safety interlocking and coarse adjustment monitoring. To reduce network latency, the host computer and the compensation system are directly connected across a single switch, without going through routing.

[0053] The master station control module achieves precise control and status feedback through two types of data structures: PWM_SET and PWM_RB. The configuration parameters (PWM_SET) include: OUTPUT_VALUE (duty cycle), SLOT (cycle length, in μs), LD_SLOT_B0 (cycle update enable), LD_SLOT_B1 / B2 (cycle mode, 0001 is cycle mode), MODE_SLOT (cycle setting activation trigger bit), SW_ENABLE (pulse start bit), TM_CTRL_DQ (automatic sequence control bit, Q point level is directly controlled by SET_DQA during reset), and RES_ERROR (fault clear bit).

[0054] The readback parameters (PWM_RB) include: fault flags ERP_PWR (power L+ missing), ERR_LD (load error), ERR_OUT_VAL (invalid duty cycle value), and ERR_SLOT_VAL (invalid cycle value); and status flags STS_READY (parameter ready), STS_SW_ENABLE (software enable feedback), STS_LD_SLOT (SLOT switching successful), STS_DQA (pulse output status), and STS_ENABLE (output sequence activated).

[0055] When the device is started for the first time or when IOC communication is re-established, the host computer needs to trigger the PWM_Start enable switch in the master station control module to take over remote control. At this time, the system automatically performs safety interlock detection: the host computer is only allowed to issue pulse control commands when the temperature of the heating resistor is lower than the target value and does not exceed the upper threshold, and the internal interlock status is normal; otherwise, the master station control module will refuse to respond and stop generating pulse signals to prevent malfunctions.

[0056] The host computer can only configure channel parameters after confirming that there are no errors in ERR_PWR and ERR_LD. When setting the duty cycle OUTPUT_VALUE and period length SLOT, if only a single period modification is required, LD_SLOT_B0 should be reset before the next polling; otherwise, it should remain set. MODE_SLOT must be set after each period modification to make the settings take effect. If the parameters are written successfully, ERR_OUT_VAL and ERR_SLOT_VAL remain reset; if they are set, it indicates that the setting has failed, and the settings must be rewritten and the fault cleared by setting RES_ERROR.

[0057] After the channel parameters are ready (STS_READY set), the host computer starts the PWM output by setting SW_ENABLE and TM_CTRL_DQ. The duty cycle resolution can reach 1 / 27648, but extremely low duty cycles are only allowed below 100Hz; above 100Hz, the upper limit needs to be recalculated. The PWM pulse drives the solid-state relay to switch on and off at a frequency of 10-100Hz and a duty cycle of 10%-100% (invisible to the human eye, requiring oscilloscope verification). When the resistor temperature approaches the target value, the main station control module releases the underlying control, handing over full control to the host computer algorithm for fine adjustment. This temperature control device, as an intermediate execution layer independent of optical detection and host computer algorithms, can provide high-precision, universal active thermal compensation functions for various mirror box devices.

[0058] This device employs a dual hardware and software safety protection mechanism. At the software level, the system has built-in temperature detection and interlocking functions. When the current temperature of the target heating module exceeds the target temperature or the current temperature of any temperature probe is outside the preset temperature threshold range, the pulse output of the corresponding channel is automatically stopped. At the hardware level, the controlled circuits of the solid-state relays support independent power-on and power-off configurations. By default, the controlled circuits of all channels are connected to the first power module. When a specific channel needs to be powered off for maintenance or isolated due to a fault, its power supply circuit can be cut off individually by unplugging the corresponding plug-in power terminal without affecting the normal operation of other channels. It should be noted that, to match the host computer control algorithm, the main station control module processes data using external interrupts to accelerate the response speed of pulse cycle and percentage.

[0059] This embodiment has the following advantages and effects: Firstly, addressing the issues of low accuracy and difficulty in achieving nanometer-level compensation in traditional temperature control solutions, this embodiment employs 20 independent PWM pulse output channels, each operating independently with a duty cycle resolution as high as 1 / 27648. Since the accuracy of the mirror's active deformation directly depends on the temperature control accuracy of the heating resistor, which in turn is determined by the fineness of the pulse adjustment, this high-resolution characteristic enables the system to precisely control minute thermal deformations, thereby breaking through the accuracy limits of conventional solutions and meeting the requirements for nanometer-level error compensation.

[0060] Secondly, addressing the issues of low integration and difficult operation and maintenance in existing systems, this embodiment highly integrates temperature control interlocks, control loops, and controlled loops, with clear and standardized wiring, significantly reducing system redundancy and wiring complexity, facilitating later maintenance and module replacement, and improving the system's scalability and reliability.

[0061] Finally, addressing the issue of poor compatibility with the control system of large scientific facilities, this embodiment uses the S7 nodave protocol to uniformly name and standardize the connection of control and feedback ports to the EPICS system. This protocol, based on S7 extensions, features high speed, high reliability, and short-cycle response, enabling the device to quickly respond to host computer commands and adapt to different operating conditions in real time, effectively achieving seamless integration with the control system of large scientific facilities.

[0062] Please see Figure 3 This application also proposes a temperature control method for mirror compensation, which is applied to the aforementioned temperature control device for mirror compensation. The specific structure of the temperature control device is as described in the above embodiments. The temperature control method for mirror compensation includes steps S10 to S60: Step S10: In response to receiving the temperature threshold setting signal from the host computer, determine the preset temperature threshold range for the M temperature probes.

[0063] Step S20: In response to receiving the target temperature signal from the host computer, determine the target temperature corresponding to each heating module.

[0064] Step S30: Determine the current temperature of the M temperature probes based on the M temperature detection signals.

[0065] Step S40: Determine the current temperature of the target heating module based on the current temperatures of the M temperature probes and the distribution positions of the N heating modules and the M temperature probes.

[0066] Step S50: When the current temperature of the target heating module has not reached the target temperature, and the current temperatures of the M temperature probes are all within the preset temperature threshold range, in response to receiving the mirror compensation signal from the host computer, the target duty cycle and target frequency corresponding to the target heating module are determined.

[0067] Step S60: Based on the target duty cycle and target frequency, output the corresponding pulse control signal to the corresponding switch control module, or send the target duty cycle and target frequency to the substation control module to control the substation control module to output the corresponding pulse control signal to the corresponding switch control module.

[0068] The temperature control method for mirror compensation provided in this application, applied to a temperature control device, can solve the technical problem of beam quality degradation caused by thermal deformation of the deflector in a high repetition frequency free electron laser environment. Compared with the prior art, the beneficial effects of the temperature control method for mirror compensation provided in this application are the same as those of the temperature control device for mirror compensation provided in the above embodiments, and will not be repeated here.

[0069] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A temperature control device for mirror compensation, characterized in that, include: Power module; N heating modules are used to heat the area of ​​the mirror to be compensated. M temperature probes are connected to the power module to detect the temperature of N heating modules and output M temperature detection signals, where M ≤ N; N switch control modules are respectively connected to the corresponding heating module and the power module, and are used to control the working status of the N heating modules; The substation control module is connected to the power supply module and the K switch control modules respectively; The main station control module is connected to M temperature probes, the substation control module, and I switch control modules, and is used to connect to the host computer; I=NK; The main station control module is configured as follows: In response to receiving a temperature threshold setting signal from the host computer, the preset temperature threshold range of the M temperature probes is determined; In response to receiving the target temperature signal from the host computer, the target temperature corresponding to the target heating module is determined; Based on the M temperature detection signals, determine the current temperature of the M temperature probes; Based on the current temperatures of the M temperature probes and the distribution positions of the N heating modules and the M temperature probes, determine the current temperature of the target heating module; When the current temperature of the target heating module has not reached the target temperature, and the current temperatures of the M temperature probes are all within the preset temperature threshold range, the target duty cycle and target frequency corresponding to the target heating module are determined in response to the mirror compensation signal received from the host computer. Based on the target duty cycle and the target frequency, a corresponding pulse control signal is output to the corresponding switch control module, or the target duty cycle and the target frequency are sent to the substation control module to control the substation control module to output a corresponding pulse control signal to the corresponding switch control module.

2. The temperature control device for mirror compensation as described in claim 1, characterized in that, Before responding to the mirror compensation signal received from the host computer, the master station control module is further configured to: In response to receiving a first power signal from the host computer, the difference between the actual beam emission power and the preset beam emission power in the specular illumination area is calculated; the first power signal represents the preset beam emission power. When the current temperature of the target heating module has not reached the target temperature, and the current temperatures of the M temperature probes are all within the preset temperature threshold range, and the difference does not exceed the preset power error range, the received mirror compensation signal is responded to. The response to the received mirror compensation signal is prohibited when at least one of the following conditions is met: the current temperature of the target heating module reaches the target temperature; the current temperature of any of the temperature probes is outside the preset temperature threshold range; and the difference exceeds the preset power error range.

3. The temperature control device for mirror compensation as described in claim 1, characterized in that, The substation control module includes: An Ethernet communication unit is connected to the main station control module via Ethernet. J pulse output units, each pulse output unit is connected to 2 of the switch control modules respectively; the J pulse output units are used to generate corresponding pulse control signals according to the received target duty cycle and target frequency and send them to the corresponding switch control modules; J is a positive integer greater than or equal to 1 / 2.

4. The temperature control device for mirror compensation as described in claim 3, characterized in that, N is an even number between 16 and 32, I is 4 or 8, and J = N / 2 - I / 2.

5. The temperature control device for mirror compensation as described in claim 3, characterized in that, The switch control module includes a solid-state relay. The controlled terminal of the solid-state relay is connected to the corresponding master station control module or the pulse output unit. The first terminal of the solid-state relay is connected to the power supply module, and the second terminal of the solid-state relay is connected to the corresponding heating module.

6. The temperature control device for mirror compensation as described in claim 2, characterized in that, The preset power error range is an adjustable parameter; the main station control module is also configured to: In response to receiving a power threshold setting signal from the host computer, the preset power error range is determined.

7. The temperature control device for mirror compensation as described in claim 6, characterized in that, The master station control module has a communication interface, and the master station control module is connected to the host computer through the communication interface; the communication interface uses a preset industrial communication protocol for data interaction. The memory of the master station control module is equipped with an address mapping table, which stores the mapping relationship between process variable addresses and communication data addresses defined by the preset industrial communication protocol; the process variable addresses include at least one of the following: a first variable address corresponding to the temperature threshold setting signal, a second variable address corresponding to the target temperature signal, a third variable address corresponding to the mirror compensation signal, and a fourth variable address corresponding to the power threshold setting signal; The master station control module is further configured to: in response to a read / write request received from the host computer via the communication interface, perform read / write operations on the corresponding first variable address, second variable address, third variable address, and fourth variable address based on the address mapping table.

8. The temperature control device for mirror compensation as described in claim 7, characterized in that, The preset industrial communication protocol includes at least one of the following: S7nodave protocol, Modbus-TCP protocol, and OPC UA protocol.

9. The temperature control device for mirror compensation as described in claim 7, characterized in that, The master station control module is also used to feed back at least one of the following status parameters through the communication interface: power failure status, parameter loading error status, duty cycle setting invalid status, frequency setting invalid status, and pulse output enable status.

10. A temperature control method for mirror compensation, characterized in that, The temperature control device with mirror compensation as described in any one of claims 1 to 9; the temperature control method with mirror compensation includes: In response to receiving a temperature threshold setting signal from the host computer, the preset temperature threshold range of the M temperature probes is determined; In response to receiving the target temperature signal from the host computer, the target temperature corresponding to the target heating module is determined; Based on the M temperature detection signals, determine the current temperature of the M temperature probes; Based on the current temperatures of the M temperature probes and the distribution positions of the N heating modules and the M temperature probes, determine the current temperature of the target heating module; When the current temperature of the target heating module has not reached the target temperature, and the current temperatures of the M temperature probes are all within the preset temperature threshold range, the target duty cycle and target frequency corresponding to the target heating module are determined in response to the mirror compensation signal received from the host computer. Based on the target duty cycle and the target frequency, a corresponding pulse control signal is output to the corresponding switch control module, or the target duty cycle and the target frequency are sent to the substation control module to control the substation control module to output a corresponding pulse control signal to the corresponding switch control module.

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