Curved surface array electrofluid nozzle control method

Abstract

The invention provides a curved surface array electrofluid nozzle control method, and relates to the technical field of electrofluid jet printing, and the method comprises the steps: processing a to-be-jet-printed image, and generating dot matrix data; nozzle opening and closing control information is generated according to the dot matrix data; generating a multi-channel nozzle driving control signal according to the nozzle opening and closing control information; in the process of outputting a multi-channel nozzle driving control signal to drive a target nozzle, under the unified space kinematics constraint and the injection time sequence constraint, controlled injection of the target nozzle under the curved surface condition is achieved by cooperatively executing track generation, injection trigger control and interference constraint control. The high-precision jet device can meet the high-precision jet requirement under the complex curved surface condition.

Description

A control method for curved array electro-hydraulic nozzles Technical Field

[0001] This invention relates to the technical field of electrohydraulic inkjet printing, and more specifically to a method for controlling a curved array electrohydraulic printhead. Background Technology

[0002] With the rapid development of flexible electronics, micro-nano manufacturing, and other fields, electrohydraulic inkjet printing technology has become one of the important technical means for precision patterning manufacturing due to its advantages such as ultra-high printing resolution, good compatibility with various functional materials, and non-contact forming. Early electrohydraulic inkjet printing systems mostly adopted a single-head structure. While this could meet basic printing requirements, it had significant shortcomings in printing efficiency, processing area, and the ability to create complex patterns, making it difficult to adapt to the development trend of large-scale manufacturing. To improve printing efficiency, electrohydraulic printheads have gradually evolved towards array-based designs. Arrayed electrohydraulic printheads, through parallel spraying from multiple printheads, can significantly improve printing efficiency per unit time and provide a technical foundation for the dot-matrix manufacturing of complex patterns. However, with the increase in the number of printheads, the control system of arrayed printheads faces a series of new technical challenges in data processing, real-time performance, and system coordination.

[0003] In existing arrayed electrohydraulic inkjet printing technology, printhead drive control usually focuses on channel-level opening and closing and voltage timing output based on dot matrix data. However, the spatial motion control and ejection triggering of the printhead are mostly coordinated by independent motion systems or empirical parameters. There is a lack of coordinated constraints on printhead pose, execution trajectory and ejection timing under a unified spatial kinematic model. Especially in the printing scenario of curved surface or flexible substrate, the attitude changes, path deviations and local curvature differences generated by the printhead during the movement are difficult to be reflected in the ejection triggering and channel drive logic in a timely manner. This can easily lead to the ejection position not matching the actual curved surface geometry, the ejection time not matching the spatial position, and even the loss of control of the distance between the printhead and the substrate or the risk of potential collision due to the lack of systematic local and global interference constraints. As a result, the printing process relies on manual parameter adjustment, and the printing stability and spatial consistency are difficult to guarantee, making it difficult to meet the high-precision ejection requirements under complex curved surface conditions. Summary of the Invention

[0004] This invention provides a method for controlling a curved surface arrayed electro-hydraulic nozzle, which can adapt to the high-precision spraying requirements under complex curved surface conditions.

[0005] A first aspect of the present invention provides a method for controlling a curved arrayed electrohydrodynamic nozzle, the method comprising: processing an image to be printed and generating dot matrix data; generating nozzle opening and closing control information based on the dot matrix data; generating a multi-channel nozzle drive control signal based on the nozzle opening and closing control information; and, in the process of outputting the multi-channel nozzle drive control signal to drive a target nozzle, under unified spatial kinematic constraints and jetting timing constraints, achieving controlled jetting of the target nozzle under curved surface conditions through coordinated execution trajectory generation, jetting trigger control, and interference constraint control.

[0006] In a second aspect, the present invention provides a curved array electro-hydraulic nozzle control device, the device being used to execute a curved array electro-hydraulic nozzle control method as described in any of the above embodiments. The device includes an acquisition module, a processing module, and an output module, wherein: the acquisition module is used to process an image to be printed and generate dot matrix data; the processing module is used to generate nozzle opening and closing control information based on the dot matrix data; the processing module is used to generate multi-channel nozzle drive control signals based on the nozzle opening and closing control information; and the output module is used to, during the process of outputting the multi-channel nozzle drive control signals to drive the target nozzle, achieve controlled spraying of the target nozzle under curved surface conditions by coordinating trajectory generation, spray trigger control, and interference constraint control under unified spatial kinematic constraints and spray timing constraints.

[0007] In a third aspect of the invention, an electronic device is provided, including a processor, a memory, a user interface, and a network interface, wherein the memory is used to store instructions, the user interface and the network interface are both used to communicate with other devices, and the processor is used to execute the instructions stored in the memory to cause the electronic device to perform the method as described in any of the preceding embodiments.

[0008] In a fourth aspect of the invention, a non-transitory computer-readable storage medium is provided, the computer-readable storage medium storing instructions that, when executed, perform the method as described in any of the preceding claims.

[0009] In summary, one or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages: 1. The present invention, under unified spatial kinematic constraints and jet timing constraints, performs collaborative modeling and linkage control of lattice data, nozzle opening and closing control, multi-channel drive signals and multi-axis execution trajectories, so that the nozzle pose, execution trajectory, jet triggering time and surface geometry are always kept consistent and correlated. In the jetting process, path correction based on surface normal and curvature characteristics and local and global interference constraints are introduced, thereby avoiding jetting position mismatch and safety gap loss caused by attitude changes, path deviations or curvature abrupt changes, so that the jetting behavior can be continuously and adaptively adjusted with the surface geometry, and finally achieve stable, accurate and spatially consistent high-precision jetting under complex surface conditions. Attached Figure Description

[0010] Figure 1 is a flowchart illustrating a curved surface arrayed current fluid nozzle control method disclosed in an embodiment of the present invention; Figure 2 is a schematic diagram illustrating a hardware and software collaborative arrayed current fluid nozzle control system disclosed in an embodiment of the present invention; Figure 3 is a flowchart illustrating an image processing procedure to be printed disclosed in an embodiment of the present invention; Figure 4 is a flowchart illustrating the generation of nozzle opening and closing control logic disclosed in an embodiment of the present invention; Figure 5 is a schematic diagram illustrating the hardware motherboard circuit configuration disclosed in an embodiment of the present invention; Figure 6 is a schematic diagram illustrating the simulation results of a dual-channel nozzle drive circuit disclosed in an embodiment of the present invention; Figure 7 is a flowchart illustrating controlled spraying of a target nozzle under curved surface conditions disclosed in an embodiment of the present invention; Figure 8 is a flowchart illustrating a collaborative execution trajectory generation process disclosed in an embodiment of the present invention; Figure 9 is a schematic diagram illustrating a method for determining the bending direction of a curved surface disclosed in an embodiment of the present invention; Figure 10 is a structural schematic diagram of an electronic device disclosed in an embodiment of the present invention.

[0011] Explanation of reference numerals in the attached figures: 1001, processor; 1002, communication bus; 1003, user interface; 1004, network interface; 1005, memory. Detailed Implementation

[0012] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0013] Although arrayed electrohydrodynamic inkjet printing has significantly improved printing efficiency and supported the manufacturing of complex patterns through parallel multi-head printing, existing technologies are still mainly limited to dot matrix driving and channel-level voltage control. They lack overall coordinated control of printhead pose, execution trajectory, and jetting timing under a unified spatial kinematic model. Especially in the printing scenarios of curved surfaces or flexible substrates, printhead posture changes, path deviations, and curvature differences cannot be effectively fed back to the jetting triggering and driving logic, which in turn leads to jetting position mismatch, timing mismatch, and potential interference risks. As a result, the printing process relies on experience-based parameter tuning, and stability and spatial consistency are difficult to guarantee, making it difficult to meet the manufacturing requirements of high-precision, continuous jetting under complex curved surface conditions.

[0014] This embodiment discloses a method for controlling a curved arrayed electrohydrodynamic nozzle. Referring to Figure 1, it includes the following steps S110-S140: S110, processing the image to be printed and generating dot matrix data.

[0015] In related technical fields, heterogeneous control architectures employing ARM processors and FPGAs working in tandem have become a common and effective technical approach. ARM processors possess strong general-purpose computing capabilities and abundant peripheral interface resources, making them suitable for undertaking upper-level tasks such as image data management, control logic scheduling, system communication, and operational status monitoring; while FPGAs, relying on their highly parallel hardware structure and deterministic timing characteristics, can achieve synchronous generation and high-speed real-time control of multi-channel nozzle drive signals.

[0016] Referring to Figure 2, this invention provides an arrayed electrostatic printhead control system based on a host computer and an ARM+FPGA heterogeneous architecture for collaborative processing. Through hardware and software collaboration, it addresses image data transmission and caching requirements, ensuring synchronous control of multiple printheads and comprehensively improving electrostatic printing efficiency, system scalability, and manufacturing precision. The host computer processes the pattern to be printed, converting the image into character dot matrix data representing the working state of the printhead array, and then sends this character dot matrix data to the ARM main control board.

[0017] The ARM main control board, as the system's control core, receives dot matrix data from the host computer and processes it. The dot matrix data characterizes the working status of the nozzle array, indicating the on / off state of each nozzle. The ARM main control board maps the dot matrix data according to the row and column distribution of the nozzle array, generating corresponding nozzle on / off control signals, and sends these signals to the FPGA controller via the bus. The ARM main control board also receives nozzle status feedback information from the FPGA control unit and analyzes and judges the system's operating status.

[0018] The FPGA controller receives the nozzle opening and closing control signals sent by the ARM main control board through the bus, generates the corresponding drive timing signals for the arrayed nozzles based on the nozzle opening and closing control signals, and outputs the drive timing signals to the nozzle drive circuit to realize the on-demand switching of the arrayed nozzles.

[0019] The nozzle drive circuit receives the drive timing signal output from the FPGA controller and converts it into a drive electrical signal that meets the operating requirements of the current-mode nozzle, thereby controlling the opening and closing of the nozzle. The nozzle drive circuit has a multi-channel structure, with each channel corresponding to a different nozzle in the nozzle array, to achieve independent drive control of the arrayed nozzles.

[0020] The nozzle status feedback circuit acquires the nozzle's status information during operation and sends it to the FPGA controller. The FPGA controller collects the received nozzle status information and sends it to the ARM main control board. The ARM main control board determines the nozzle's operating status based on this information. When an abnormal nozzle status is detected, the ARM main control board controls the system to stop the nozzle drive or enter a safety protection state.

[0021] The preprocessing of the pattern to be printed by the host computer includes image scaling, image grayscale conversion, image filtering, image binarization, and image character mapping. Image scaling matches the resolution of the input image with the physical resolution of the printhead array to ensure that the output dot matrix data corresponds to the printing area. Image grayscale conversion converts the input color image or multi-channel image into a single-channel grayscale image for subsequent filtering and binarization. Image filtering performs noise reduction and enhancement on the grayscale image to improve the robustness and stability of binarization. The image binarization module converts the grayscale image into the binarized image required for printing. Image character mapping transforms continuous regions into discrete character arrays based on the binarized image, generating the dot matrix corresponding to the printhead array. The image character mapping process requires traversing every pixel of the binary image data and converting the dot matrix information of the image into the corresponding character encoding based on the printhead distribution information.

[0022] The ARM main control board includes: a host computer communication module, a control logic generation module, an FPGA communication module, and a system security control module. The host computer communication module facilitates data interaction between the ARM control unit and the host computer, receiving printing-related data and control commands from the host computer and providing feedback on system operating status information. Furthermore, the host computer communication module receives image-processed character dot matrix data, printing parameter configuration data, and system control commands, performing integrity verification and cache management on the received data to ensure reliable and real-time data transmission. Simultaneously, the host computer communication module also sends system operating status, printhead working status, and abnormal alarm information to the host computer, enabling the host computer to monitor and manage the printing process. The control logic generation module parses and processes the received character dot matrix data and generates corresponding printhead opening and closing control logic based on the spatial distribution of the printhead array. The control logic generation module traverses the character array according to a preset scanning order and maps the two-dimensional dot matrix information in the character array to control status information corresponding one-to-one with the printhead array channels. Through this processing, the character dot matrix data is converted into the nozzle's opening and closing logic matrix. The FPGA communication module is used to realize data interaction between the ARM main controller and the FPGA control unit, sending the nozzle opening and closing control data generated by the control logic generation module to the FPGA control unit, and receiving status feedback information returned by the FPGA.

[0023] Furthermore, the FPGA communication module achieves high-speed transmission and synchronization of control data through a preset bus interface, enabling the FPGA to generate corresponding nozzle drive timing signals based on the received control information. Simultaneously, the FPGA communication module also receives nozzle status feedback data acquired or processed by the FPGA and transmits it to the system safety control module for further processing.

[0024] The system safety control module monitors and assesses the system's operational status to ensure the safe and stable operation of the arrayed nozzle system. It receives nozzle status feedback and analyzes the system's operating status. When an abnormal state is detected, the module triggers a protection mechanism to restrict or interrupt the nozzle drive process, thereby preventing system damage or abnormal spraying. The module also sends alarm information to the host computer when an anomaly occurs and records relevant status data for subsequent system diagnosis and maintenance.

[0025] The FPGA controller includes: a data receiving and parsing module, a control signal generation module, a printhead drive timing generation module, and a printhead status acquisition module. The data receiving and buffering module receives printhead opening and closing control data from the ARM control unit and buffers the data to obtain control information corresponding to each channel of the printhead array. The control signal generation module generates basic control signals for the printhead based on the printhead control information output by the data receiving and buffering module, representing the open or closed state of each printhead channel during the current printing cycle. The control signal generation module organizes and distributes the control information according to the channel configuration relationship of the printhead array, forming a set of control signals corresponding to the printhead array structure, thereby realizing independent or coordinated control of the arrayed fluid printheads. The printhead drive timing generation module performs timing processing on the basic control signals output by the control signal generation module, generating timing control signals that meet the printhead drive requirements. The printhead drive timing generation module can synchronize and coordinate the drive signals of multiple printheads according to preset drive cycles and timing rules, thereby ensuring the timing consistency and stability of the arrayed printheads during the printing process.

[0026] The nozzle status acquisition module receives and collects status information from the nozzle status acquisition circuit during the nozzle drive process, and outputs this information to the upper control unit for monitoring system operation and safety assessment. The status information collected by the nozzle status acquisition module reflects the nozzle's operating status, enabling the triggering of corresponding protection or control measures when the nozzle malfunctions or deviates from preset conditions.

[0027] The nozzle drive circuit adopts a SiC MOSFET half-bridge drive circuit, which receives the high voltage waveform generated by the high voltage power supply and controls whether the nozzle is connected to the high voltage according to the control signal generated by the FPGA main controller, thereby realizing the independent control of the arrayed current fluid nozzle.

[0028] The printhead status acquisition circuit is used to acquire key electrical parameters related to the printing status during the printhead driving process, so as to obtain status information reflecting the working status of the electro-hydraulic printhead.

[0029] The printhead status acquisition circuit is primarily used to collect voltage status information applied to the electro-hydraulic printhead. As a crucial control parameter affecting the electro-hydraulic ejection behavior, changes in applied voltage directly reflect the printhead's operating status and the stability of the printing process. This provides the upper-level control unit with a basis for determining whether the printhead is in a normal ejection state, triggering corresponding protection or control measures when the voltage is abnormal, deviates from the preset range, or does not match control commands.

[0030] The dot matrix coordinate reference is used to discretize the printing area into a regular grid consistent with the row and column channel arrangement of the target printhead. First, the channel arrangement parameters of the target printhead are fixed. The channel arrangement parameters include at least the number of rows and columns, the row channel numbering rules, the column channel numbering rules, and the channel physical spacing parameters. The basic grid spacing of the dot matrix coordinate reference is defined by the channel physical spacing parameters. At the same time, the incremental direction of the row index and column index of the dot matrix coordinate reference is defined by the row channel numbering rules and the column channel numbering rules, so that the dot matrix coordinate reference always uses the same coordinate caliber in its representation, avoiding ambiguity when the same channel is referenced by different indices when generating subsequent printhead opening and closing control information. Among them, the dot matrix coordinate reference refers to the discrete coordinate system used to describe which row and column of the spray unit, the row and column channel arrangement refers to the set of spray channels of the target printhead arranged in rows and columns in the physical structure, and the channel identifier refers to the number or index that can uniquely identify a certain spray channel.

[0031] The correspondence between the dot matrix coordinate reference and the projection range of the printing area in the workpiece coordinate system is used to map the continuous spatial position in the workpiece coordinate system to the discrete row and column indices of the dot matrix coordinate reference. First, the projection boundary of the printing area is determined in the workpiece coordinate system. The projection boundary includes at least the coordinates of the projection start point, the coordinates of the projection end point, and the reference axis selection of the projection direction. Based on the projection boundary, a linear mapping relationship from the workpiece coordinate system to the dot matrix coordinate reference is constructed, so that the coordinates of any landing point in the workpiece coordinate system can be converted into the dot matrix row index and the dot matrix array index. Furthermore, the dot matrix row index and the dot matrix array index are mapped to the channel identifier according to the channel arrangement rules, so that the dot matrix coordinates are logically directly mapped to the channel identifier of the target printhead. The workpiece coordinate system refers to the spatial coordinate system established with the workpiece or substrate as a reference. The projection range refers to the coverage area of ​​the printing area on the specified plane of the workpiece coordinate system. The linear mapping refers to the mapping method of converting continuous coordinates into discrete indices through scaling factors and zero-point offset.

[0032] In the formula, x and y represent the coordinates of a certain spray landing point in the workpiece coordinate system within the projection plane. and Indicates the coordinates of the starting point of the printed area projection. and The grid spacing represents the reference grid coordinates in the row and column directions. i and j represent the row index and array index of the grid, respectively. This mapping is achieved by segmenting continuous spatial coordinates according to the grid spacing and taking the segment number, so that each discrete unit can be stably bound to a unique channel identifier and used for subsequent channel opening and closing control.

[0033] Referring to Figure 3, the preprocessing of the image to be printed is used to convert the original pattern into a printable image that can directly participate in dot matrix and spraying determination. By performing format normalization and resolution matching on the input pattern, a consistent correspondence is established between the pixel matrix and the grid spacing of the dot matrix coordinate reference. The multi-channel color information is uniformly mapped to single-channel brightness information through grayscale expression conversion, thereby reducing the impact of color differences on subsequent threshold segmentation. On this basis, noise suppression and necessary edge preservation enhancement processing are performed on the grayscale image to weaken random noise and brightness disturbances and maintain clear pattern boundaries, so that the printable image is suitable for stable determination of spraying requirements in terms of brightness distribution and structural features. Subsequently, the printed image is divided into spraying and non-spraying areas through binarization processing. Continuous grayscale changes are converted into pixel-level binary judgment results based on a global threshold or adaptive threshold. Then, raster sampling is performed on the binarized image under the constraint of a dot matrix coordinate reference. Valid spraying judgment results are generated by aggregating the proportion of binary pixels within the sampling unit. Finally, the valid spraying judgment results are encoded into dot matrix data or dot matrix frame sequences corresponding one-to-one with the printhead channels according to a row and column structure. This transforms the spraying requirement from a continuous image representation into discrete control data that can directly drive the printhead opening and closing control. It should be noted that the relevant content in the above technical solution is only a conventional technical means in the prior art, and therefore will not be elaborated further here.

[0034] In one possible implementation, referring to Figure 4, a flowchart illustrates an ARM scanning character array and the generation of arrayed printhead control logic. First, the ARM main control board receives image dot matrix data and printhead array structure information from the host computer. The printhead array information includes the number of rows and columns of the printheads, used to determine the correspondence between the dot matrix data and the printhead array. After receiving the data, the ARM main control board initializes the dot matrix scanning process, sets the starting position of the dot matrix scan, and initializes the scan row and column indices to initial values ​​as the position identifiers of the currently processed dot matrix units. Subsequently, based on the number of rows and columns of the printhead array, the ARM main control board reads the dot matrix unit data corresponding to the current scanning position from the dot matrix data and performs a validity check on the dot matrix unit to determine whether it is a valid printhead. When the check result is a valid printhead, the ARM main control board generates the corresponding printhead's on / off control logic for the current printing cycle; when the check result is an invalid printhead, it generates the corresponding printhead's off control logic for the current printing cycle.

[0035] The generated on / off control logic is written into the printhead control logic set for the current printing cycle. After generating the control logic corresponding to the current dot matrix unit, the ARM main control board updates the dot matrix scan index, switches to the next dot matrix position to be processed, and determines whether all dot matrix data has been scanned. If not, it returns to read the next dot matrix unit and repeats the above judgment and control logic generation process; if all dot matrix data has been scanned, it forms a printhead control logic data array based on the generated printhead control logic set. Finally, the ARM main control board sends the printhead control logic data array to the FPGA controller for subsequent generation of printhead drive timing and execution of printing, completing the dot matrix scan and printhead control logic generation process.

[0036] The ARM main control board and the FPGA controller communicate via the AXI4 bus, and the circuit configuration of the hardware motherboard is shown in Figure 5. The FPGA controller uses the Altera Cyclone IV series device EP4CE10F17C8N as the core control chip to implement the low-level control and status management of the arrayed current fluid printheads. The FPGA interacts with the ARM main control board via the AXI4 bus and has built a printhead control register group and a data buffer unit inside. The ARM main control board writes the opening and closing control data corresponding to each printhead channel into the register space or transmits it to the internal logic module of the FPGA via the FIFO buffer. Based on the received control data, the FPGA generates the corresponding printhead channel drive control signal in the hardware logic layer through programmable counters, comparators, and timing state machines. In this embodiment, the drive control signal is implemented in the form of a PWM waveform, and its period, duty cycle, and enable state can be configured by register parameters. The PWM signal is scheduled by the timing control logic (PLL) in a unified clock domain to ensure the synchronization and consistency of the multi-channel printheads in the same printing cycle. Meanwhile, the FPGA is also connected to the nozzle status information acquisition board to receive status feedback signals from each nozzle channel. These feedback signals enter the FPGA via an input register or sampling buffer unit and are compared in real-time with a preset threshold register, thus determining at the hardware level whether each nozzle channel is in normal working condition. When an abnormal state is detected in a nozzle channel, the FPGA can immediately disable the corresponding channel's PWM output through a control state machine and write the abnormality judgment result into the status register. This result is then fed back to the ARM main control board via the AXI4 bus, enabling coordinated operation of nozzle driving, status judgment, and timing control.

[0037] S120 generates nozzle opening and closing control information based on dot matrix data.

[0038] Channel mapping rules are used to stably map the discrete row and column indices of the dot matrix data to the channel identifiers of the target nozzles, thereby ensuring that the one-to-one association between dot matrix units and nozzle channels remains unchanged throughout the entire process. The correspondence between row indices and row-direction channel numbers, and the correspondence between column indices and column-direction channel numbers, must be consistent with the physical arrangement of the target nozzles. The physical arrangement includes at least the number of rows and columns of the nozzle array, the row-direction numbering direction, the column-direction numbering direction, and channel organization constraints such as whether there is serpentine wiring or group wiring. To avoid assigning different numbers to the same channel at different processing stages, the channel mapping rules are fixed as deterministic functions and maintain the same function caliber throughout the entire period of the dot matrix frame sequence, so that subsequent nozzle opening and closing control information, drive frame sequences, and multi-channel nozzle drive control signals can share the same channel identifier system.

[0039] The dot matrix frame sequence describes the time-sequential dot matrix requirements that advance with the printing cycle. Its core is to establish a strict correspondence between spatial dot matrix data and the printing cycle on the time axis. The temporal order of the dot matrix frame sequence is consistent with the printing cycle progression. The target dot matrix frame corresponding to the current printing cycle is obtained by indexing the printing cycle identifier and is consistent with the scanning strategy and step size settings used when generating the dot matrix data on the upper-level side. When reading the target dot matrix frame, both the dot matrix frame identifier and the printing cycle identifier are read simultaneously. This ensures that the subsequently generated printhead opening and closing control information can be traced back to the specific printing cycle in time and can maintain the same cycle diameter with the synchronous triggering of the motion system's spraying, avoiding spraying position misalignment caused by dot matrix frame errors, skipped frames, or repeated frames.

[0040] The preset scanning strategy defines the traversal order of dot matrix units within the target dot matrix frame, ensuring that the traversal order aligns with the relative motion direction of the target nozzle and the spraying cycle. The relative motion direction reflects the scanning direction of the nozzle relative to the workpiece, while the spraying cycle reflects the correspondence between the printing cycle and the interpolation cycle or trigger cycle. Together, they determine when and in what order the channel opening and closing states should be loaded within the same printing cycle. Common scanning strategies include row-first or column-first, forward or reverse scanning, and serpentine traversal constraints such as whether adjacent rows use reverse retracement. Serpentine traversal reduces the zero-travel of the motion platform and lowers the risk of cycle breakage. The traversal resolution result needs to be consistent with the channel mapping rules, enabling the dot matrix unit index obtained during traversal to be directly converted into channel identifiers, further forming the target control state of the corresponding channel within the printing cycle. By formalizing the scanning strategy into a mapping relationship, the traversal order can be bound to the relative motion direction and spraying cycle, ensuring reversibility between the traversal sequence number and the dot matrix unit index, thereby avoiding channel mismatch caused by index drift during traversal.

[0041] The effective jetting determination result indicates whether a dot matrix unit needs to trigger jetting within the current printing cycle. It originates from the unit-level aggregation determination after rasterization sampling of the binarized image in the previous stage. Therefore, the effective jetting determination result maintains the same spatial discreteness as the dot matrix coordinate reference. When reading the effective jetting determination result, the data read is not pixel-level data but dot matrix unit-level data, causing the parsing overhead to increase proportionally with the number of printhead channels, making it more suitable for array-based real-time control. To ensure that the correspondence between the read result and the target dot matrix frame is not disrupted, the dot matrix frame identifier remains unchanged during the reading process. When data consistency verification is required, the dot matrix frame verification field is used to determine whether the dot matrix frame has completely arrived at the control side, avoiding the reading of incomplete dot matrix frames under conditions of communication jitter or buffer overlay, which could lead to the printhead channel being opened or closed incorrectly.

[0042] The target control state is used to convert the valid spray determination result into the on / off semantics of the printhead channel within the current printing cycle, enabling the control side to directly perform channel gating based on the target control state in the hardware timing. The printhead open control state corresponds to the valid spray determination result, and the printhead close control state corresponds to the invalid spray determination result. This mapping relationship remains unique and unchanged throughout the entire process, avoiding the same determination result being interpreted as different control semantics at different stages. To be compatible with the timing organization of subsequent multi-channel printhead drive control signals, the target control state not only expresses on / off states but also needs to be aligned with the loading time of the printing cycle. This ensures that the target control state has been loaded and is in a stable state that can be called by the gating logic before the spray synchronization trigger arrives, thereby avoiding spray jitter or missed spray caused by the channel state still flipping when the trigger arrives. By first mapping the dot matrix unit to the channel identifier and then mapping the determination result to the channel control state, a traceable conversion from spatial dot matrix requirements to channel on / off semantics is achieved, and the conversion process is ensured to be closed and consistent on the index link.

[0043] Printhead opening and closing control information needs to be traceable and alignable. Therefore, binding the target control state with the channel identifier, dot matrix frame identifier, and printing cycle identifier is used to form a complete control record structure. The channel identifier is used to identify the controlled object, the dot matrix frame identifier is used to identify the control source, and the printing cycle identifier is used to identify the control activation time. After binding these three, it is possible to quickly locate whether the problem is a dot matrix frame misalignment, a channel mapping error, or a printing cycle alignment error when missed printing, reprinting, or timing deviation occurs. The binding structure also provides direct material for the subsequent generation of drive frame sequences, enabling multi-channel printhead drive control signals to be batch loaded according to the same printing cycle identifier and output synchronously under a unified clock reference. At the same time, it enables safety mechanisms such as abnormal channel shielding and frame consistency verification to accurately locate the control range that needs to be shielded or retransmitted based on the dot matrix frame identifier and the printing cycle identifier. By binding the control state of each channel with the source frame and activation cycle and organizing it into a set structure, the printhead opening and closing control information has a complete three-element association of object, source, and timing.

[0044] S130 generates multi-channel nozzle drive control signals based on nozzle opening and closing control information.

[0045] Channel alignment processing eliminates the discrepancies between the software-side and hardware-side channel identifiers in printhead opening and closing control information, ensuring that the driver side can interpret and directly load this information using the same channel identifier. Differences in channel identifiers typically manifest as different row and column expansion orders, different channel starting numbers, and different channel rearrangements due to hardware wiring. Therefore, channel alignment processing, based on channel mapping rules and overlaid with a hardware rearrangement mapping table, converts the channel identifiers in the printhead opening and closing control information into driver-side channel indices. After conversion, these indices are organized into a driver frame sequence according to the printing cycle order. Each driver frame contains the target control states of all printhead channels within the same printing cycle, and the frame order in the driver frame sequence matches the printing cycle progression order. This ensures that the driver side can locate a unique driver frame and output the corresponding channel state at any given time simply by using the printing cycle identifier. In channel alignment processing, a driver frame refers to a timing data unit that encapsulates the opening and closing states of all printhead channels within a printing cycle, and a driver frame sequence refers to a set of driver frames arranged consecutively according to the printing cycle. This mapping rearranges the logical channel numbers on the software side to the physical channel order on the hardware side, so that any target control state can accurately fall on the corresponding drive output channel.

[0046] In one possible implementation, referring to Figure 6, this embodiment uses a high-voltage half-bridge drive circuit to control the arrayed current-current nozzles. Each nozzle channel corresponds to a half-bridge structure composed of a pair of SiC MOSFETs, used to achieve rapid loading and release of high voltage in the nozzle. The PWM signal output by the FPGA is amplified by an isolated gate driver chip and drives the upper and lower bridge MOSFETs respectively. During spraying, the high-voltage power supply is connected to the nozzle, and when spraying stops, the voltage at the nozzle terminal is quickly pulled down, thereby achieving high-speed switching of the nozzle voltage state. To ensure operational safety, an overcurrent detection and fast shutdown mechanism is set in the half-bridge circuit, triggering protection when the channel current is abnormal. The system simultaneously generates the high-voltage drive signal required for spraying through a high-voltage amplification link, and adopts a compact wiring, gate limiting, and high-voltage isolation design to improve the stability of high-voltage switching. The nozzle voltage acquisition module isolates and samples the actual operating voltage of the nozzle and digitizes it, and feeds the acquisition results back to the FPGA and ARM main controller for real-time judgment of the nozzle operating status and to achieve safe monitoring and control of the spraying process. It should be noted that the relevant content in the above technical solution is only a conventional technical means in the prior art, and therefore will not be described further here.

[0047] Furthermore, the time correlation between the drive frame and the printing cycle identifier is used to bind the effective time of the drive frame to the start time of the printing cycle, ensuring that the drive frame loading, spray synchronization triggering, and motion trajectory advancement are on the same time reference. This time correlation is achieved by carrying the printing cycle identifier in the drive frame and maintaining a printing cycle counter on the drive side. The printing cycle counter increments at the beginning of each printing cycle and triggers the drive frame reading logic, loading the target control state in the current drive frame into the channel control state array. The channel control state array refers to the channel state storage structure consistent with the row and column arrangement of the arrayed fluid printheads. Each array element uniquely corresponds to a printhead channel and remains stable within a printing cycle until it is overwritten by the next drive frame at the start of the next printing cycle, thus ensuring that the opening and closing states within the printing cycle do not transiently flip due to loading jitter. The key to the time correlation is ensuring that the start of the printing cycle has a deterministic triggering relationship with the drive frame reading and loading, allowing the channel control state array to enter a stable state before the spray triggering occurs. This relationship loads the correct set of target control states at the start of each printing cycle by translating time progression into printing cycle progression, and further translating printing cycle progression into drive frame selection.

[0048] The abnormal channel shielding state and system safety control strategy are combined to apply a forced shutdown constraint to the nozzle channel with abnormalities on the drive side, preventing the abnormal channel from continuing to output drive carriers in the open control state, which could lead to jetting runaway or electrical risks. The abnormal channel shielding state typically originates from channel-level status feedback, overvoltage and overcurrent detection, abnormal nozzle-end voltage readback, or continuous periodic jetting failure determination, and is manifested as a shielding flag for a specified channel. The system safety control strategy defines the triggering conditions, maintenance conditions, and recovery conditions for shielding, making the shielding behavior traceable and recoverable. The merging operation is performed after the channel control state array is loaded. By using the shielding flag as a priori constraint for gating, the target control state of the shielded channel is forcibly rewritten to a closed control state and remains unchanged during the printing cycle. This ensures that regardless of the target control state given to the channel by the upstream drive frame, the drive carrier will not be allowed to pass to the channel in the final output stage. The abnormal channel shielding state refers to the prohibited output state flag for the nozzle channel, and the system safety control strategy refers to the set of constraint rules used to determine abnormal judgment and linkage protection actions.

[0049] The base drive carrier provides a unified timing basis for channel driving, ensuring consistent edge alignment across multiple channels within the same clock domain. The drive parameter set defines key timing attributes of the base drive carrier, such as frequency, duty cycle, phase reference, period boundary alignment, and minimum on-hold, establishing a consistent time constraint with the printing cycle. This ensures the base drive carrier repeats a defined number of times or exists within a defined window during the printing cycle. For arrayed fluid printheads, the base drive carrier is typically used in conjunction with a gated interface of the high-voltage drive stage. The base drive carrier first generates a low-voltage timing signal in the logic domain, which is then level-shifted and amplitude-loaded by the subsequent high-voltage drive circuit. The drive parameter set is fixed through configurable registers or configuration tables, ensuring a consistent carrier configuration across different periods for the same printing task and allowing adaptive adjustments within the limits of the safety policy. The base drive carrier refers to the unified timing carrier generated before channel opening / closing constraints are applied, while the drive parameter set refers to the set of parameters used to determine the timing configuration and boundary conditions of this carrier.

[0050] Channel-level gating is used to superimpose constraints from a channel control state array onto the basic drive carrier. This allows printhead channels in the open control state to output their corresponding drive carriers, while preventing printhead channels in the closed control state from outputting drive carriers, thus forming a multi-channel printhead drive control signal. Logically, channel-level gating uses the channel control state array as an enable mask, independently executing carrier release or carrier blocking for each channel. When it's necessary to suppress inter-channel coupling, it superimposes interlocking constraints between adjacent channels, ensuring that simultaneous release of adjacent channels within the same time window meets preset limits. The resulting multi-channel printhead drive control signal is time-coordinated with the basic drive carrier and spatially corresponds one-to-one with the channel control state array. This ensures that the channel opening / closing semantics for each printing cycle are strictly converted into hardware-executable signals indicating whether each channel outputs a drive carrier within that cycle. Channel-level gating refers to a control mechanism that releases or blocks carriers channel-by-channel based on the channel's enable state. The multi-channel printhead drive control signal refers to the set of timing signals ultimately output to the drive circuit interface, capable of controlling all printhead channels in parallel. This relationship achieves multiplicative gating of the basic drive carrier and the channel control state, ensuring that the output is always 0 when the channel is in the closed control state or is shielded, and that the output follows the basic drive carrier when the channel is in the open control state and is not shielded. This transforms the opening and closing control semantics within the printing cycle into a multi-channel drive control signal that can be output in parallel.

[0051] S140, in the process of outputting multi-channel nozzle drive control signals to drive the target nozzle, achieves controlled spraying of the target nozzle under curved surface conditions through coordinated execution trajectory generation, spray trigger control and interference constraint control under unified spatial kinematic constraints and spray timing constraints.

[0052] Referring to Figure 7, for multi-segment consistent printing on curved or flexible substrates, the collaborative mechanism of dot matrix data and printhead array spatial mapping can be used to cope with printing errors caused by geometric distortion and local gap changes. For example, when performing high-resolution patterning on the elastomer substrate of wearable devices, the curved carrier of thin-film antennas, and the non-planar substrate of microlens arrays, the effective distance from the printhead to the substrate and the local electric field distribution will change with curvature and warping.

[0053] Three-dimensional geometric description information is used to fully characterize the spatial morphology and local curvature changes of the target substrate within the printing area, providing a computationally achievable geometric basis for subsequent surface spraying path planning, spray point location determination, and interference constraint determination. The three-dimensional geometric description information can be expressed as surface point clouds, triangular meshes, or parametric surfaces, with one representation method consistently used within the same task to maintain data consistency. Surface point clouds represent the surface morphology using discrete sampling point sets, triangular meshes represent the surface topology and local normals using sets of triangular faces, and parametric surfaces represent the continuous geometric properties of the surface using parametric equations. The printing area defines the spatial range to be sprayed and corresponds to a climaxable subset in the three-dimensional geometric description information, ensuring that subsequent processing is performed only within the printing area to reduce computational burden and avoid invalid path generation.

[0054] Surface representation is used to unify 3D geometric description information under the same spatial reference of the workpiece coordinate system, thus giving the spray path, spray point position, and trigger determination unique semantics in the workpiece coordinate system. The workpiece coordinate system, as the bearing coordinate system of the surface representation, requires its origin and axial direction definitions to be consistent with the clamping datum of the target substrate. The machine tool coordinate system, as the execution coordinate system of the multi-axis motion platform, requires its origin and axial direction definitions to be consistent with the zero-return datum of the motion platform. The installation pose is used to characterize the fixed assembly relationship of the target nozzle relative to the machine tool coordinate system, including the translational offset of the nozzle reference point relative to the origin of the machine tool coordinate system and the rotational offset of the nozzle axis relative to the axial direction of the machine tool coordinate system. Multi-level pose transformation relationships are used to map the surface representation in the workpiece coordinate system to the axis position constraints in the machine tool coordinate system, and reflect the axis positions in the machine tool coordinate system back to the nozzle spatial position in the workpiece coordinate system. This ensures that subsequent interpolation and inverse kinematics solutions share the same coordinate transformation link, avoiding spray position mismatch caused by the surface representation and the nozzle execution trajectory being in different coordinate apertures.

[0055] The dot matrix coordinate reference is used to discretize the spatial requirements of the curved surface printing task into a regular grid consistent with the row and column arrangement structure of the target printhead, enabling the dot matrix unit to serve as the smallest spatial granularity for printhead channel control. The projection range of the surface in the workpiece coordinate system is used to determine the coverage boundary of the dot matrix coordinate reference. The projection range is obtained by mapping the curved surface printing area onto the projection plane along a selected projection direction, and the row and column index values ​​of the dot matrix coordinate reference are limited by the projection start and end points. The row and column arrangement structure provides the discrete resolution and channel alignment basis for the dot matrix coordinate reference. It includes at least the number of row channels, the number of column channels, the row channel spacing, and the column channel spacing, ensuring that the grid spacing of the dot matrix coordinate reference is consistent with the physical spacing or equivalent coverage spacing of the printhead channels. Surface parameters characterize geometric properties such as local normals, curvature, or surface parameter coordinates. The association between the dot matrix coordinate reference and surface parameters ensures that the dot matrix unit carries the corresponding surface geometric information synchronously during generation, thereby enabling the subsequent spray point position to be uniquely located on the surface and supporting interference constraint determination.

[0056] Discrete mapping processing is used to map the two-dimensional pattern semantics of the image to be printed into discrete spraying semantics of dot matrix data. This allows each dot matrix unit in the dot matrix data to be simultaneously associated with a channel identifier and a surface target spraying position. The channel identifier uniquely identifies the spraying channel of the target nozzle, while the surface target spraying position uniquely identifies the spray landing point or the center of the spraying window on the surface representation of the workpiece coordinate system. Discrete mapping processing must be completed under the constraints of the dot matrix coordinate reference, ensuring that the row and column indices of each dot matrix unit can determine the channel identifier through channel mapping rules. Simultaneously, the surface target spraying position is determined through surface projection inverse calculation or surface parameter solving, thus forming a closed-loop association link between dot matrix unit, channel identifier, and surface target spraying position. The output of discrete mapping processing is solidified in the form of dot matrix data, eliminating the need for repeated surface solving when generating nozzle opening and closing control information. Instead, the association results in the dot matrix data are directly read to maintain real-time performance.

[0057] The dot matrix frame sequence is used to organize the dot matrix data into a temporal sequence that progresses with the printing cycle, ensuring that the spatial discreteness requirements of curved surface jetting are consistent with the temporal progression requirements of motion scanning. The curved surface jetting path sequence defines the scanning order of curved surface coverage, and the dot matrix frame sequence is arranged in this order, establishing a one-to-one correspondence between the dot matrix frame identifier and the progress position on the curved surface jetting path. The relative motion direction describes the scanning direction of the target printhead relative to the target substrate, the motion speed describes the magnitude of the scanning process, and the jetting step distance describes the interval between adjacent jetting trigger positions. These three factors together determine the correspondence between the printing cycle and the spatial progression. The consistency between the dot matrix frame sequence and the relative motion direction, motion speed, and jetting step distance means that the spatial coverage increment corresponding to each dot matrix frame is consistent with the displacement increment of the motion platform within a printing cycle. This ensures that the jetting trigger moment and the dot matrix frame switching moment are aligned under a unified time reference, avoiding jetting point drift caused by asynchrony between motion progression and dot matrix frame progression.

[0058] Channel mapping rules are used to convert dot matrix units in a dot matrix frame sequence into channel-level control semantics for the target nozzle. Nozzle opening / closing control information is used to indicate whether each channel is in an open or closed state within the spray cycle. The channel mapping rules are based on the fixed correspondence between row and column indices of the dot matrix data and row-to-column channel numbers, ensuring that each dot matrix unit can be uniquely identified within any spray cycle. When converting a dot matrix frame sequence into nozzle opening / closing control information, the dot matrix frames are read frame by frame, and the dot matrix units are traversed according to a preset scanning strategy. Valid spray determination results are read and mapped to an open or closed state. This state is then bound to the channel identifier, dot matrix frame identifier, and printing cycle identifier to form traceable nozzle opening / closing control information. The spray cycle characterizes the time granularity of spray triggering, maintaining the same cycle caliber as the printing cycle or forming a defined frequency doubling relationship. This ensures that the nozzle opening / closing control information is stably effective within the spray cycle and aligned with the gating logic of subsequent multi-channel nozzle drive control signals, thereby guaranteeing consistency between channel opening / closing semantics, spray triggering semantics, and execution trajectory semantics under curved surface spraying conditions.

[0059] The continuous execution trajectory provides a continuous sequence of axis positions for the multi-axis motion platform during the spraying process, ensuring that the target nozzle simultaneously satisfies positional and attitude constraints on the curved surface spraying path. Multi-level pose transformation relationships map the spraying point pose in the workpiece coordinate system to the axis positions and angles in the machine tool coordinate system, maintaining consistency between the continuous execution trajectory and the curved surface representation in coordinate semantics. RTCP interpolation compensation compensates for pose coupling errors introduced by the rotation axis, ensuring that the spatial trajectory of the target nozzle's tool center point in the workpiece coordinate system does not deviate due to axis changes. The interpolation period defines the temporal granularity of interpolation calculation and trajectory update. The current position refers to the position coordinates of the target nozzle in the workpiece coordinate system determined by the interpolation output within the interpolation period, while the corresponding spraying position refers to the curved surface target spraying position bound to the current printing cycle in the dot matrix frame sequence. The position comparison-based injection synchronization trigger control determines the spatial relationship between the current position and the corresponding injection position, outputs an injection trigger signal, and aligns this signal with the interpolation period. This ensures that injection only occurs within the spatial window when the target nozzle reaches the corresponding injection position, avoiding injection point drift caused by asynchrony between dot matrix frame advancement and motion advancement. Multi-level pose transformation relationships, continuous execution trajectories, and dot matrix frame sequences are correlated within the same workpiece coordinate system, enabling the injection synchronization trigger control to directly constrain the timing output using spatial criteria, thereby establishing a rigid coupling relationship between spatial position and injection timing.

[0060] The surface offset path planning result is used to provide a set of surface spraying paths covering the target surface and to provide a correctable geometric reference for the continuous execution trajectory, ensuring that the continuous execution trajectory maintains consistent coverage in curvature change regions, boundary transition regions, and surface splicing regions. Continuous execution trajectory correction refers to introducing path planning constraints on the original interpolation output to ensure that the spatial projection of the execution trajectory is consistent with the surface spraying path. Simultaneously, the offset spacing and path sequence in the path planning are mapped to the printing cycle progression law, thereby ensuring that the spatial correspondence between the dot matrix frame sequence and the execution trajectory is not disrupted. Local interference determination is used to constrain the target nozzle from local proximity or collision near the spraying point due to excessive local curvature of the surface. The equivalent radius simplifies the target nozzle shape to comparable equivalent size parameters, and the normal curvature radius characterizes the local bending radius of the surface along the relevant direction at the spraying point. Comparing these two parameters determines whether the local geometry of the surface allows the target nozzle to maintain an acceptable spraying gap in the current posture. Global interference determination is used to ensure that the minimum clearance between the overall shape of the target nozzle and the curved surface is not lower than the safety threshold. The minimum distance from the axis to the curved surface characterizes the minimum spatial clearance between the target nozzle and the curved surface along the nozzle axis in the current attitude. The equivalent radius serves as the minimum safe clearance threshold to determine whether there is a collision risk. Local interference determination and global interference determination together constitute the interference constraint system. The former covers the local interference risk caused by curvature, while the latter covers the global collision risk caused by the overall attitude, ensuring that continuous execution trajectories can simultaneously satisfy path coverage and safe clearance constraints during correction.

[0061] The coordinated constraints of execution trajectory, dot matrix data, and printhead opening / closing control information are used to establish a closed and consistent relationship between three types of information: the location of the target printhead, whether spraying is required at that position, and which channels need to be opened, within the same printing cycle. This allows the output of the multi-channel printhead drive control signal to be matched with the curved surface spraying task both spatially and temporally. The execution trajectory provides the target axis position within the interpolation cycle and determines the evolution of the current position over time. The dot matrix data provides the spatial binding relationship between the curved surface target spraying position and the channel identifiers. The printhead opening / closing control information provides the open or closed status of each channel within the spraying cycle and aligns with the printing cycle identifiers. The coordinated output of the multi-channel nozzle drive control signal is manifested by using the interpolation period determined by the execution trajectory as the time reference, determining the injection allowable window by injection synchronization trigger control based on position comparison, determining the channel-level gating mask by nozzle opening and closing control information, and outputting drive carriers to channels in the open state and prohibiting the output of drive carriers to channels in the closed state within the injection allowable window. This makes the multi-channel nozzle drive control signal consistent with the dot matrix frame sequence in terms of injection time and injection position, consistent with the nozzle opening and closing control information in the channel dimension, and consistent with the continuous execution trajectory in the motion dimension, ultimately achieving continuous, stable and spatially consistent controlled injection under curved surface conditions.

[0062] In one possible implementation, referring to Figure 8, during the collaborative trajectory generation process, firstly, a surface representation model uniformly mapped to the workpiece coordinate system is established based on the substrate to be sprayed for the image to be printed. The surface representation model is used to describe the three-dimensional morphology of the substrate under unified geometric semantics, enabling the image to be printed to be accurately mapped to the spraying position in real space. The substrate to be sprayed is modeled as a continuously defined surface object in the workpiece coordinate system. This surface is represented by parametric equations, mesh models, or equivalent geometric expressions, and is consistently bound to the workpiece clamping datum, ensuring that the position coordinates, tangential direction, normal direction, and curvature characteristics of any point on the surface can be stably calculated. Through this surface representation model, the target spraying position formed after the image to be printed undergoes rasterization can find a unique corresponding surface point in the workpiece coordinate system, thus providing a unified geometric basis for subsequent path generation, offset processing, and interference determination. The workpiece coordinate system is used to describe the static spatial reference frame of the spraying substrate, and the surface representation model is used as the geometric carrier for the spraying content.

[0063] Furthermore, referring to Figure 9, the bending direction of the surface curve is determined by combining the direction of the surface normal vector and the normal curvature. At any point on the surface, a unique surface normal vector is first determined as a reference direction. Then, the normal curvature of the curve at that point is calculated along the given curve direction. When the normal curvature is positive, it indicates that the surface curve at that point bends towards the side where the normal vector is located along the tangent of the curve; that is, the curve bends towards the same side as the normal vector. When the normal curvature is negative, it indicates that the surface curve at that point bends away from the side where the normal vector is located along the tangent of the curve; that is, the curve bends towards the opposite side of the normal vector. When the normal curvature is zero, it indicates that the surface curve does not bend in that direction and presents a locally approximate straight state. Through this determination method, the concavity / convexity and bending direction of the surface curve near a point can be accurately determined based solely on local normal and curvature information without relying on global geometry.

[0064] The reference plane is used to transform the preset spray direction into a spatial object that can be geometrically constrained with the surface to generate the initial spray path on the surface. The preset spray direction is represented as a fixed direction vector in the workpiece coordinate system. The reference plane is constructed using this direction vector and a given spatial position, so that the reference plane has a definite orientation and position in space. By performing an intersection operation on the reference plane and the surface representation model, one or more continuous intersection lines are obtained on the surface. This intersection line serves as the initial spray path, which naturally satisfies the surface geometric constraints and inherits the overall trend of the spray direction, thereby avoiding the path from deviating from the surface or exhibiting discontinuities. The initial spray path serves as the geometric starting point for subsequent path offsetting and discretization processing.

[0065] Successive offset processing is used to extend the initial spray path on the surface to cover the entire target surface. The offset direction is determined by the path tangent and the surface normal, ensuring that the offset always lies within the surface tangent plane and is consistent with the surface normal, thus guaranteeing that the offset path still strictly conforms to the surface shape. The offset distance is determined based on the nozzle's allowable spray width and the safe distance between the nozzle and the surface, to form reasonable coverage between adjacent paths without excessive overlap or gaps. By using the previous path as a new reference path and repeating the offset process, multiple surface spray paths are gradually generated until the set of paths covers the target spray area within the surface parameter domain. At the same time, a fixed path order is assigned to each path to constrain the scanning logic for subsequent spray point generation and trajectory advancement.

[0066] Parametric iterative segmentation is used to transform a continuous curved surface spray path into a discrete sequence of spray points, enabling the path to be executed by a multi-axis motion platform in the form of discrete interpolation. The continuous path is described by a single parameter in the parameter domain. By recursively dividing the path parameter interval under a given approximation error threshold constraint, the geometric approximation error of the connection between adjacent spray points to the original curve does not exceed the threshold. When the curvature of the surface changes significantly, the parametric segmentation is automatically refined to improve spatial fitting accuracy. When the curvature changes gently, the parametric segmentation is automatically relaxed to reduce the number of spray points, thereby establishing a balance between spray accuracy and spray efficiency. Finally, a sequence of spray points arranged in the path order is formed, which describes the set of discrete target spray positions of the nozzle on the curved surface.

[0067] Local interference determination is used to constrain the geometric matching relationship between the nozzle and the surface at the injection point scale, so as to avoid the nozzle from getting too close or scraping in local high curvature areas. The normal radius of curvature is used to characterize the local bending ability of the surface along the path direction at the injection point, and the equivalent radius is used to convert the nozzle shape dimensions into comparable geometric parameters in the interference analysis. By comparing the size relationship between the normal radius of curvature and the equivalent radius, and combining the concavity and convexity of the surface near the point, it is determined whether the nozzle will produce local curvature interference under the condition of maintaining a given posture and injection gap. Thus, injection points that do not meet the local geometric constraints are eliminated in the injection point generation stage, ensuring the feasibility of the subsequent execution trajectory at the local scale.

[0068] Global interference determination is used to constrain the minimum safe clearance between the nozzle and the surface from the overall spatial scale to avoid collision between the nozzle and the surface in a certain posture. The target nozzle axis is used to describe the center direction of the nozzle in space, and the minimum distance is used to quantify the closest clearance between the axis and the surface representation model. By calculating the minimum distance from the target nozzle axis to the surface representation model in the spray posture and comparing this distance with the equivalent radius, it can be determined whether there is a risk of overall collision with the nozzle. Only when the minimum distance is greater than the equivalent radius is the target spray point determined to satisfy the global interference constraint, thereby ensuring the safe movement of the nozzle within the overall spatial range during spray execution.

[0069] Multi-level pose transformation relationships are used to map the pose of a target spraying point in the workpiece coordinate system to an executable target pose in the machine tool coordinate system. The spatial position represents the three-dimensional coordinates of the spraying point in the workpiece coordinate system, and the attitude represents the directional constraint of the nozzle at the spraying point, which is usually determined by the relationship between the nozzle axis and the surface normal. The multi-level pose transformation relationship describes the assembly offset and motion coupling relationship between the workpiece coordinate system, the machine tool coordinate system, and the intermediate rotation coordinate system through the cascaded form of translation transformation matrix and rotation transformation matrix. This ensures that each target spraying point obtains a unique corresponding target pose in the machine tool coordinate system after mapping, thereby providing a consistent spatial input for inverse kinematics solution and interpolation control.

[0070] The five-axis RTCP interpolation model is used to generate the execution trajectory of a multi-axis motion platform in the machine tool coordinate system, ensuring that the tool center point of the target nozzle moves strictly along the surface spraying path in the workpiece coordinate system. The synchronous interpolation of displacement coordinates and rotation coordinates is used to ensure that the linear axis and rotation axis advance in tandem within the same interpolation cycle. The nonlinear spatial deviation is used to describe the coupling effect of the rotation axis change on the tool center point position. By compensating for the nonlinear spatial deviation during the interpolation process and superimposing it into the linear axis interpolation result, trajectory correction in the sense of RTCP is achieved, so that the generated execution trajectory can still maintain the consistency between the spray point position, nozzle attitude and surface geometry under complex surface conditions, thus forming the final collaborative execution trajectory.

[0071] Furthermore, on the one hand, the dot matrix data required for array-based inkjet printing is large in scale and complex in structure, involving multiple stages such as image processing and printhead control logic construction. If only low-level real-time controllers such as FPGAs complete all data processing tasks, it will put a lot of pressure on their logic and storage resources, making it difficult to meet the real-time requirements of high-speed inkjet printing. On the other hand, if the host computer completes all data processing and directly sends out complete dot matrix data, it will generate a large data transmission pressure, occupy communication bandwidth, and increase the data buffer burden of the lower-level system, which is not conducive to the stable operation of the system. On the other hand, in the independent drive mode of array-based printheads, each printhead channel needs to apply a drive voltage under a strictly consistent time reference. If the control system lacks a unified timing coordination mechanism, it is easy to cause deviations in the jetting timing between printheads, thereby affecting the consistency and repeatability of the printed pattern.

[0072] This embodiment also discloses a curved surface arrayed electro-hydraulic nozzle control device, including an acquisition module, a processing module, and an output module. The device is used to execute any of the curved surface arrayed electro-hydraulic nozzle control methods described above, wherein: the acquisition module is used to process the image to be printed and generate dot matrix data; the processing module is used to generate nozzle opening and closing control information based on the dot matrix data; the processing module is used to generate multi-channel nozzle drive control signals based on the nozzle opening and closing control information; and the output module is used to achieve controlled spraying of the target nozzle under curved surface conditions by coordinating trajectory generation, spray trigger control, and interference constraint control under unified spatial kinematic constraints and spray timing constraints during the output of multi-channel nozzle drive control signals to drive the target nozzle.

[0073] It should be noted that the above embodiments of the apparatus are only illustrated by the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the apparatus and method embodiments provided in the above embodiments belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0074] This embodiment also discloses an electronic device. Referring to FIG10, the electronic device may include: at least one processor 1001, at least one communication bus 1002, user interface 1003, network interface 1004, and at least one memory 1005.

[0075] The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen and a camera. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface). The processor 1001 may include one or more processing cores. The processor 1001 connects to various parts of the server using various interfaces and lines, and performs various server functions and processes data by running or executing instructions, programs, code sets, or instruction sets stored in the memory 1005, and by calling data stored in the memory 1005. Optionally, the processor 1001 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 1001 may integrate one or a combination of several of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), and modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the content to be displayed on the screen; and the modem handles wireless communication. It is understood that the modem may not be integrated into the processor 1001 and can be implemented as a separate chip.

[0076] The above are merely exemplary embodiments of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Those skilled in the art will readily conceive of other embodiments of this disclosure upon considering the specification and the disclosure of practical truths. This invention is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described in this disclosure.

Claims

1. A method for controlling a curved array electrohydrodynamic nozzle, characterized in that, The method includes: processing the image to be printed and generating dot matrix data; generating printhead opening and closing control information based on the dot matrix data; generating multi-channel printhead drive control signals based on the printhead opening and closing control information; and, in the process of outputting the multi-channel printhead drive control signals to drive the target printhead, under unified spatial kinematic constraints and jetting timing constraints, achieving controlled jetting of the target printhead under curved surface conditions through coordinated execution trajectory generation, jetting trigger control, and interference constraint control.

2. The method for controlling a curved array electro-hydraulic nozzle according to claim 1, characterized in that, The process of processing the image to be printed and generating dot matrix data specifically includes: establishing a dot matrix coordinate reference consistent with the row and column channel arrangement of the target printhead; establishing a correspondence between the dot matrix coordinate reference and the projection range of the printing area in the workpiece coordinate system, so that the dot matrix coordinates are mapped to the channel identifier of the target printhead; performing preprocessing on the image to be printed to obtain a printed image; performing binarization processing on the printed image to distinguish between the sprayed area and the non-sprayed area, selecting the corresponding threshold generation method according to the grayscale distribution characteristics of the printing area, and obtaining a binarized image; performing raster sampling on the binarized image according to the dot matrix coordinate reference, generating a corresponding valid spraying determination result for each sampling unit; and encoding the valid spraying determination result into dot matrix data with a fixed row and column structure, so that each element in the dot matrix data corresponds one-to-one with the channel identifier.

3. The method for controlling a curved array electro-hydraulic nozzle according to claim 2, characterized in that, The preprocessing of the image to be printed to obtain the printed image specifically includes: scaling the image to be printed to obtain a scaled image; converting the scaled image to grayscale to obtain a grayscale image; and performing noise reduction and enhancement processing on the grayscale image to obtain a filtered image, thus obtaining the printed image.

4. The method for controlling a curved array electro-hydraulic nozzle according to claim 1, characterized in that, The step of generating printhead opening and closing control information based on the dot matrix data specifically includes: determining a channel mapping rule consistent with the physical arrangement of the target printhead based on the correspondence established between the row index of the dot matrix data and the row channel number of the target printhead, and the column index of the dot matrix data and the column channel number of the target printhead, thereby associating each dot matrix unit with the corresponding printhead channel; reading the target dot matrix frame corresponding to the current printing cycle according to the time sequence of the dot matrix frame sequence, wherein the dot matrix frame sequence is based on the generation of the dot matrix data and organizes the dot matrix data into a sequence generated as the printing cycle progresses; and scanning the dot matrix data according to a preset scanning strategy. Each dot matrix unit in the target dot matrix frame is traversed and parsed to ensure that the traversal order is consistent with the relative movement direction and spray rhythm of the target printhead. When traversing each dot matrix unit, the corresponding valid spray determination result is read. Based on the valid spray determination result, the target control state of the corresponding printhead channel in the current printing cycle is generated, wherein the determination result indicating valid spray is mapped to the printhead open control state, and the determination result indicating invalid spray is mapped to the printhead close control state. The target control state is bound to the channel identifier, dot matrix frame identifier, and printing cycle identifier of the target printhead to form the printhead open / close control information.

5. The method for controlling a curved array electro-hydraulic nozzle according to claim 1, characterized in that, The step of generating a multi-channel printhead drive control signal based on the printhead opening and closing control information specifically includes: performing channel alignment processing on the printhead opening and closing control information and organizing it into a drive frame sequence according to the printing cycle order, so that each drive frame corresponds to the target control state of all printhead channels within the same printing cycle; establishing a time association between the printing cycle identifier corresponding to each drive frame in the drive frame sequence, and loading the target control state in the current drive frame into a channel control state array consistent with the row and column arrangement of the arrayed fluid printheads at the beginning of each printing cycle; merging the abnormal channel shielding state and the system safety control strategy into the channel control state array to perform forced shutdown constraints on printhead channels with abnormalities; generating a basic drive carrier based on a preset set of drive parameters after the channel control state array is effective; controlling the basic drive carrier through channel-level gating, so that printhead channels in the open control state output the corresponding drive carrier, and printhead channels in the closed control state are prohibited from outputting drive carriers, thereby forming the multi-channel printhead drive control signal.

6. The method for controlling a curved array electro-hydraulic nozzle according to claim 1, characterized in that, The method further includes: establishing a surface representation model that is uniformly mapped to the workpiece coordinate system based on the substrate to be sprayed for the image to be printed; constructing a reference plane corresponding to a preset spraying direction in the workpiece coordinate system, and generating an initial spraying path on the surface by performing an intersection operation between the reference plane and the surface representation model; performing successive offset processing on the initial spraying path along an offset direction that is consistent with the surface normal and perpendicular to the tangent of the initial spraying path to form a set of surface spraying paths covering the target surface, and establishing a path order for each surface spraying path; for each path in the set of surface spraying paths, performing parametric iterative segmentation processing on the continuous curve path under a given approximation error threshold to generate spraying paths arranged according to the path order. In the process of generating the injection point sequence, local interference is determined by comparing the normal radius of curvature of the surface at the injection point with the equivalent radius of the target nozzle; global interference is determined by calculating the relationship between the minimum distance from the target nozzle axis to the surface representation model and the equivalent radius, so as to filter target injection points that meet the execution conditions; the multi-level pose transformation relationship between the target injection point and the workpiece coordinate system and the machine tool coordinate system is associated, and the spatial position and attitude of the target injection point are mapped to the machine tool coordinate system; in the machine tool coordinate system, the displacement coordinates and rotation coordinates between adjacent target injection points are synchronously interpolated using a five-axis RTCP interpolation model, and the nonlinear spatial deviation introduced by the rotation axis is compensated to generate the cooperative execution trajectory.

7. The method for controlling a curved array electro-hydraulic nozzle according to claim 1, characterized in that, In the process of outputting the multi-channel nozzle drive control signal to drive the target nozzle, under unified spatial kinematic constraints and jetting timing constraints, controlled jetting of the target nozzle under curved surface conditions is achieved through coordinated execution trajectory generation, jetting trigger control, and interference constraint control. Specifically, this includes: acquiring the three-dimensional geometric description information of the target substrate within the printing area; mapping the three-dimensional geometric description information to the workpiece coordinate system to form a curved surface representation, determining the installation pose of the target nozzle in the machine tool coordinate system, thereby establishing a multi-level pose transformation relationship between the workpiece coordinate system and the machine tool coordinate system; constructing a dot matrix coordinate reference associated with the curved surface parameters based on the projection range of the curved surface in the workpiece coordinate system and the row and column arrangement structure of the target nozzle; performing discrete mapping processing on the image to be printed under the constraints of the dot matrix coordinate reference, so that each dot matrix unit in the dot matrix data is simultaneously associated with the channel identifier of the target nozzle and the curved surface target jetting position; organizing the dot matrix data into a dot matrix frame sequence according to the curved surface jetting path order, and making the dot matrix frame sequence associated with the target nozzle... The relative motion direction, motion speed, and spray step distance are kept consistent; the dot matrix frame sequence is converted into nozzle opening and closing control information through channel mapping rules, so that the nozzle opening and closing control information is used to indicate the open or closed state of the target nozzle in each spray cycle; during the spraying process, the continuous execution trajectory of the target nozzle is calculated by combining RTCP interpolation compensation under the constraints of the multi-level pose transformation relationship, and in each interpolation cycle, the spatial relationship between the current position of the target nozzle in the workpiece coordinate system and the corresponding spraying position in the dot matrix frame sequence is compared to execute spraying synchronization trigger control based on position comparison; the continuous execution trajectory is corrected by combining the surface offset path planning results, and the relationship between the equivalent radius of the target nozzle and the normal curvature radius of the surface is constrained by local interference judgment, and the relationship between the minimum distance from the axis of the target nozzle to the surface and the equivalent radius is constrained by global interference judgment; after completing the coordinated constraints of the execution trajectory, dot matrix data, and nozzle opening and closing control information, multi-channel nozzle drive control signals are output in a coordinated manner according to the execution trajectory.

8. A control device for a curved array electrohydraulic nozzle, characterized in that, The device is used to execute a curved surface arrayed electrohydrodynamic nozzle control method as described in any one of claims 1-7. The device includes an acquisition module, a processing module, and an output module, wherein: the acquisition module is used to process the image to be printed and generate dot matrix data; the processing module is used to generate nozzle opening and closing control information based on the dot matrix data; the processing module is used to generate multi-channel nozzle drive control signals based on the nozzle opening and closing control information; and the output module is used to, during the process of outputting the multi-channel nozzle drive control signals to drive the target nozzle, achieve controlled spraying of the target nozzle under curved surface conditions by coordinating trajectory generation, spray trigger control, and interference constraint control under unified spatial kinematic constraints and spray timing constraints.

9. An electronic device, characterized in that, The device includes a processor, a communication bus, a user interface, a network interface, and a memory. The memory is used to store instructions. The user interface and the network interface are both used to communicate with other devices. The communication bus is used to enable communication between the components within the electronic device. The processor is used to execute the instructions stored in the memory to cause the electronic device to perform the method as described in any one of claims 1-7.

10. A non-transitory computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed, perform the method as described in any one of claims 1-7.

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