Electrostatic spraying safety control method based on process task scheduling

Abstract

The application provides an electrostatic spraying safety control method based on process task scheduling, and relates to the technical field of electrostatic spraying, and comprises the following steps: receiving a task execution sequence comprising at least two process tasks; according to a current Nth process task to be executed, calling a process database to obtain a spraying process parameter set associated with the Nth process task and a safety switching strategy corresponding to the Nth process task; if N=1, controlling a gas path control module and a high-voltage electrostatic control module to directly enter a parameter state represented by a spraying process parameter set associated with the first process task; if N>1, controlling the device to perform a switching process according to the safety switching strategies corresponding to the N-1th process task and the Nth process task; after switching, controlling the gas path control module and the high-voltage electrostatic control module to maintain operation in a parameter state represented by a spraying process parameter set associated with the Nth process task; and repeatedly executing the above steps until all process tasks in the task execution sequence are executed.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of electrostatic spraying, and in particular to an electrostatic spraying safety control method based on process task scheduling. BACKGROUND

[0002] The existing electrostatic spraying control device, such as the technical solution disclosed in CN213690293U, usually adopts a static formula management mode based on the type of equipment. Specifically, the device calls corresponding preset formula parameters according to the type of spraying equipment (such as an automatic powder gun or a manual powder gun). When it is identified as an automatic device, a fixed formula parameter set is called; when it is identified as a manual device, an operator selects a formula parameter set from a storage module. This one-device-one-formula or manual selection formula control logic exposes a significant defect in actual automated production lines:

[0003] It cannot support the same spraying equipment to continuously execute multiple spraying tasks with different process parameters without interruption and re-identification. For example, when the production line needs to spray two different workpieces in turn, or different regions of the same workpiece adopt differential processes, the existing solution either needs an external system to frequently simulate a device type switching signal, or can only interrupt the operation and manually intervene, which seriously limits the flexibility and automation level of the production line, and lacks safety definition and protection for the coordinated transformation process of the gas circuit and electrostatic parameters during multi-task switching. SUMMARY

[0004] In view of the above defects or deficiencies in the prior art, the application aims to provide an electrostatic spraying safety control method based on process task scheduling, applied to an electrostatic spraying control device, the device comprising a main control unit, a storage module, a gas circuit control module connected with the main control unit, and a high-voltage electrostatic control module; the method comprises the following steps:

[0005] Receiving a task execution sequence comprising at least two process tasks;

[0006] According to the current Nth process task to be executed, calling a process database to obtain the spraying process parameter set associated therewith and the safety switching strategy corresponding thereto;

[0007] If N=1, control the gas circuit control module and the high-voltage electrostatic control module to directly enter the parameter state represented by the spraying process parameter set associated with the first process task;

[0008] If N>1, the device is controlled to perform a switching process according to the safety switching strategy corresponding to the (N-1)th process task and the Nth process task respectively; after switching, the gas path control module and the high-voltage electrostatic control module are controlled to maintain running in the parameter state represented by the spraying process parameter set associated with the Nth process task;

[0009] The above steps are repeatedly performed until all process tasks in the task execution sequence are executed;

[0010] The spraying process parameter set includes the gas path parameter executed by the gas path control module and the electrostatic parameter executed by the high-voltage electrostatic control module; the safety switching strategy specifies the coordinated action sequence and time relationship of the gas path parameter and the electrostatic parameter in state conversion.

[0011] According to the technical scheme provided in the present application, the control of the device according to the safety switching strategy corresponding to the (N-1)th process task and the Nth process task respectively to perform a switching process includes the following steps:

[0012] Performing a first parameter adjustment stage: according to the safety switching strategy, the high-voltage electrostatic control module is controlled to adjust the electrostatic parameter from the first steady-state value corresponding to the (N-1)th process task to a preset intermediate safety value or zero value;

[0013] Performing a second parameter adjustment stage: after the first parameter adjustment stage is completed, according to the safety switching strategy, the gas path control module is controlled to adjust the gas path parameter from the second steady-state value corresponding to the (N-1)th process task to the first target steady-state value corresponding to the Nth process task;

[0014] Performing a third parameter adjustment stage: after the second parameter adjustment stage is completed and the gas path parameter is stable, according to the safety switching strategy, the high-voltage electrostatic control module is controlled to adjust the electrostatic parameter from the preset intermediate safety value or zero value to the second target steady-state value corresponding to the Nth process task.

[0015] According to the technical scheme provided in the present application, in the first parameter adjustment stage and / or the third parameter adjustment stage, the process of controlling the high-voltage electrostatic control module to adjust the electrostatic parameter includes the following steps:

[0016] Obtaining the real-time load current of the high-voltage electrostatic control module;

[0017] Based on the real-time load current and a preset safety current threshold, the adjustment rate of the electrostatic parameter is dynamically adjusted;

[0018] Wherein, when the real-time load current exceeds the preset safety current threshold, the adjustment rate of the electrostatic parameter is reduced until the real-time load current falls within the preset safety current threshold.

[0019] According to the technical scheme provided in the present application, the adjustment of the electrostatic parameter from the preset intermediate safety value or zero value to the second target steady-state value corresponding to the Nth process task comprises the following steps:

[0020] The voltage ramp-up is started, and the output voltage of the high-voltage electrostatic control module is increased at a first increasing rate from the intermediate safety value or zero value;

[0021] During the voltage ramp-up, the output current change rate of the high-voltage electrostatic control module is monitored in real time;

[0022] When the output current change rate is monitored to exceed a preset first threshold value representing the stable establishment of corona discharge, the actual establishment point of the electrostatic field is determined, and the actual voltage value at this time is recorded as the basic working point voltage;

[0023] Based on the basic working point voltage and the second target steady-state value, a voltage difference value is calculated;

[0024] According to the voltage difference value, the output voltage is adjusted from the basic working point voltage to the second target steady-state value at a second increasing rate smaller than the first increasing rate.

[0025] According to the technical scheme provided in the present application, in the second parameter adjustment phase, the process of controlling the gas path control module to adjust the gas path parameter comprises the following steps:

[0026] At least one state parameter representing the stability of powder conveying is obtained in real time;

[0027] It is judged whether the state parameter has reached a target stable range associated with the Nth process task;

[0028] If not, the current gas path control instruction is maintained and the monitoring is continued; if yes, it is determined that the second parameter adjustment phase is completed, and a trigger signal is generated to start the third parameter adjustment phase;

[0029] Wherein, the state parameter includes a powder flow instantaneous fluctuation value, a gas pressure change gradient in the powder feeding pipe, or a powder cloud concentration indirectly measured by a sensor.

[0030] According to the technical scheme provided in the present application, the process database is established by the following method:

[0031] A reference process task is selected as a target process task;

[0032] controlling the device to run with the spraying process parameter set of the reference process task, and keeping the gas path parameters and electrostatic parameters stable;

[0033] During the stable running, a series of preset parameter disturbances of different types are applied to the gas path control module and / or the high-voltage electrostatic control module, and the changes of the spraying quality indicators are monitored in real time;

[0034] Based on the response relationship between the parameter disturbances and the changes of the spraying quality indicators, a multi-parameter sensitivity model is constructed to characterize the stability of the reference process task;

[0035] Based on the multi-parameter sensitivity model, a corresponding safety switching strategy is generated for the reference process task; wherein the coordinated action sequence and time relationship of the gas path parameters and the electrostatic parameters specified in the safety switching strategy are configured to actively avoid or compensate for the high-sensitivity coupling relationship identified in the multi-parameter sensitivity model during the switching process;

[0036] The reference process task, its spraying process parameter set, its corresponding multi-parameter sensitivity model and safety switching strategy are associated to obtain the process database.

[0037] According to the technical scheme provided in the present application, after the second parameter adjustment phase is determined to be completed and the third parameter adjustment phase is started, the step of performing the starting voltage ramp-up is further included before the step of performing the starting voltage ramp-up:

[0038] Obtain first coordination state information representing the actual coordination state between the electric field intensity at the outlet of the spray gun and the powder-air flow field pattern;

[0039] Based on the first coordination state information, evaluate the matching degree between it and the desired theoretical coordination state of the Nth process task;

[0040] When the matching degree is lower than the preset standard, at least one calibration parameter is generated according to the matching degree;

[0041] Based on the calibration parameter, adjust the execution parameter or execution timing of the third parameter adjustment phase.

[0042] According to the technical scheme provided in the present application, the first coordination state information representing the actual coordination state between the electric field intensity at the outlet of the spray gun and the powder-air flow field pattern is obtained by the following steps:

[0043] Send a control instruction to the high-voltage electrostatic control module to output a calibration high-voltage signal lower than the corona onset voltage threshold;

[0044] acquire, synchronously, a first physical quantity signal reflecting a transient electric field distribution and a second physical quantity signal reflecting a transient flow field distribution during the duration of the calibration high-voltage signal;

[0045] fuse the first physical quantity signal and the second physical quantity signal to obtain the first collaborative state information.

[0046] According to the technical scheme provided in the application, the first threshold value is a dynamic threshold value retrieved from the process database based on the identification information of the Nth process task; the dynamic threshold value is a current change rate threshold value determined according to the response relationship between the parameter perturbation and the change of the spraying quality index in the process of constructing the multi-parameter sensitivity model associated with the Nth process task.

[0047] The technical scheme provided in the application further includes the following steps:

[0048] If the output current change rate is monitored to exceed a preset second threshold value before the output voltage reaches the basic operating point voltage, it is determined that an abnormal discharge event occurs, and the following operations are performed:

[0049] suspend the voltage ramp-up;

[0050] control the high-voltage electrostatic control module to reduce the output voltage to a fault safety voltage lower than the intermediate safety value and maintain for a first time period;

[0051] after the first time period ends, re-perform the step of starting the voltage ramp-up;

[0052] The second threshold value is greater than the first threshold value and is related to the powder type and environmental humidity information associated with the Nth process task.

[0053] Compared with the prior art, the application has the following beneficial effects:

[0054] I. Improve the flexibility and automation level of the production line: the present application realizes the decoupling of process control and physical equipment by introducing process tasks and task execution sequences. The same spraying equipment can automatically and continuously execute multiple spraying tasks with different process parameters according to the pre-arranged sequence, without interruption or external analog switching, which significantly adapts to the flexible production demand of multi-variety and small batch.

[0055] Secondly, the safe and controllable process dynamic switching is realized: by presetting the "safe switching strategy" for each process task, the coordinated action sequence and time relationship of the gas path parameter and the static parameter adjustment during task switching are clearly specified. This enables the system to dynamically switch the working state according to the established and safe principles when performing a complex multi-task sequence, effectively avoiding the process quality defects or electrical risks that may be caused by parameter mutation.

[0056] Thirdly, the accuracy and consistency of process execution are ensured: the method automatically calls the spraying process parameter set associated with the task and the safety strategy through the master control unit, and strictly controls the execution according to the strategy, reducing the uncertainty and operation threshold of human intervention, and ensuring the process accuracy and result consistency of each task switching and steady-state operation. BRIEF DESCRIPTION OF DRAWINGS

[0057] Figure 1 The step flow chart of the electrostatic spraying safety control method based on process task scheduling provided in the present application is shown. DETAILED DESCRIPTION

[0058] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are only intended to explain the related application, and not to limit the application. In addition, it should be noted that only the parts related to the application are shown in the drawings for ease of description.

[0059] It should be noted that the examples in the present application and the features in the examples can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and examples.

[0060] Example 1

[0061] As mentioned in the background, in view of the problems in the prior art, the present application proposes an electrostatic spraying safety control method based on process task scheduling, which is applied to an electrostatic spraying control device. The device includes a master control unit, a storage module, a gas path control module connected to the master control unit, and a high-voltage static control module. As shown in Figure 1 The method includes the following steps:

[0062] S1, receiving a task execution sequence including at least two process tasks;

[0063] S2, according to the Nth process task to be executed, calling the process database to obtain the spraying process parameter set associated therewith and the safety switching strategy corresponding thereto;

[0064] S31, if N = 1, then control the gas path control module and the high-voltage static control module to directly enter the parameter state represented by the spraying process parameter set associated with the first process task;

[0065] S32, if N>1, controlling the device to perform a switching process according to the safety switching strategy corresponding to the (N-1)th process task and the Nth process task respectively; after switching, controlling the gas path control module and the high-voltage electrostatic control module to maintain running in the parameter state represented by the set of spraying process parameters associated with the Nth process task;

[0066] Further, the safety switching strategy associated with each process task is a composite control rule set, the content of which can be logically divided into at least two parts: exit association rule: define how the device should safely and orderly exit from its current steady-state parameters when this process task is switched out as the source task, usually including the order and rate of electrostatic parameter revocation, the transition mode of gas path parameters, etc. Entry association rule: define how the device should safely and orderly enter its set steady-state parameters from some intermediate or safe state when this process task is switched in as the target task, usually including the establishment order and stability judgment of gas path parameters, the reconstruction order and rate of electrostatic parameters, etc.

[0067] The execution logic of the switching process: when switching from the (N-1)th process task to the Nth process task, the switching process consists of two logically continuous and coordinated sub-processes: the first sub-process (exit source task): controlling the device to perform the operation of exiting from the parameter state corresponding to the (N-1)th process task according to the exit association rule in the safety switching strategy corresponding to the (N-1)th process task. This process aims to guide the system, especially the high-voltage electrostatic system, to a pre-set intermediate state or zero state that is safe for subsequent adjustment. The second sub-process (enter target task): after completing the first sub-process, controlling the device to perform the operation of entering the parameter state corresponding to the Nth process task according to the entry association rule in the safety switching strategy corresponding to the Nth process task. This process aims to safely and stably reconstruct the electrostatic field based on the new gas path target parameters.

[0068] S4, repeating the above steps until all process tasks in the task execution sequence are executed;

[0069] Wherein, the set of spraying process parameters includes gas path parameters executed by the gas path control module and electrostatic parameters executed by the high-voltage electrostatic control module; the safety switching strategy specifies the coordinated action order and time relationship of the gas path parameters and the electrostatic parameters when the state is converted.

[0070] Specifically, Process Task: refers to a complete spraying operation unit with a specific process objective. In this invention, a process task not only includes the final spraying effect requirement to be achieved, but is also embodied as an executable data object. This data object contains at least one set of spraying process parameters and a safety switching strategy bound to it. For example, Task A (primer rapid covering), Task B (topcoat fine modification), and Task C (local re-spraying) are three different process tasks. Task Execution Sequence: refers to an ordered list arranged according to a predetermined logic (such as time sequence, external trigger conditions) of multiple process tasks. It is arranged and issued by an upstream production management system (such as MES) or an operator, indicating which task the spraying equipment should execute first and which task it should execute later. For example, sequence [Task A→Task B→Task C]. Set of Spraying Process Parameters: a structured data set that defines all the key device setting values required to implement a certain process task. Its core includes: Gas path parameters: parameters executed by the gas path control module, such as powder feeding gas pressure (controls powder output), atomizing gas pressure (controls powder atomization fineness), shaping gas pressure / flow (controls spray shape), etc. Electrostatic parameters: parameters executed by the high-voltage electrostatic control module, mainly output voltage and / or output current limits, used to establish the electrostatic field required for adsorbing powder. Safety switching strategy: the core control rule introduced in this invention, which is not a simple parameter value, but a set of program logic or rule set. It explicitly specifies that when switching from one process task (source state) to another process task (target state), the gas path parameters and electrostatic parameters should be changed in what order (coordinated action sequence) and time rhythm (time relationship). For example, the strategy may specify that when switching, the voltage must first be reduced to 0V at a slope S1, wait for T1 milliseconds, then adjust the powder feeding gas pressure from P1 to P2, and finally, after the gas pressure stabilizes, raise the voltage to V2 at a slope S2.

[0071] Step Implementation Description:

[0072] Receive Task Execution Sequence: the master control unit (such as an industrial PLC or embedded controller) receives an ordered list containing at least two process task IDs from the host computer through a communication interface (such as Ethernet, PROFINET, CANopen). The controller stores this sequence in memory and sets a pointer N initialized to 1, pointing to the first task to be executed.

[0073] Call Process Database: the controller queries the process database (stored in a storage module such as an SD card or Flash) according to the process task ID corresponding to the current pointer N. The database returns two key data associated with this ID: one is the target spraying process parameter set, and the other is the safety switching strategy that needs to be followed when this task is used as the target of switching.

[0074] Initial task execution (N=1): If this is the first task in the sequence, the controller does not need to consider the switching process. It directly parses the spray process parameter set and simultaneously sends instructions to the gas path control module (drive proportional valve, flow meter, etc.) and the high-voltage electrostatic control module (digital high-voltage generator), so that both reach the first target steady-state value defined by the parameter set at one time. This is equivalent to the cold start or the beginning of a new job of the system.

[0075] Task switching execution (N>1): If subsequent tasks need to be executed, the controller will perform dynamic switching. At this time, it not only calls the safety switching strategy of the Nth task itself, but also needs to combine the state of the N-1th task. The controller takes the steady-state parameters of the N-1th task as the starting point of the switching, and takes the parameter set of the Nth task as the end point, and strictly follows the coordinated action sequence and time relationship defined by the two task strategies or combined by the system arbitration, to command the gas path and high-voltage electrostatic module to perform orderly parameter transition. After the switching is completed, the system runs stably under the parameters of the Nth task.

[0076] Sequence iteration: After the current task is executed (which can be determined by time, external signal or internal logic), the controller increases N by 1, and repeats steps S2-S4 until all task IDs in the sequence have been processed, thereby completing the multi-pass spray process of a complex workpiece.

[0077] The technical principle is described as follows: First, it decouples the complex spray process into discrete, parameterized task objects. Then, it recombines them into a continuous production process on the time axis by executing the sequence. The most critical step is to introduce the safety switching strategy, which is essentially a safety operation procedure for state space migration. This strategy defines a safe path and speed planning in the multi-dimensional parameter space (gas path, electrostatic) from one point (task N-1) to another point (task N), thereby avoiding process defects (such as sagging, orange peel) or equipment risks (such as high-voltage sparking, powder accumulation) caused by parameter mutation and timing disorder during the switching process.

[0078] In a preferred embodiment, the control of the device according to the safety switching strategy corresponding to the N-1th process task and the Nth process task respectively includes the following steps:

[0079] Performing a first parameter adjustment phase: according to the safety switching strategy, controlling the high-voltage electrostatic control module to adjust the electrostatic parameter from the first steady-state value corresponding to the N-1th process task to a preset intermediate safe value or zero value;

[0080] performing a second parameter adjustment stage: after the first parameter adjustment stage is completed, according to the safe switching strategy, the gas path control module is controlled to adjust the gas path parameter from the second steady-state value corresponding to the N-1th process task to the first target steady-state value corresponding to the Nth process task;

[0081] performing a third parameter adjustment stage: after the second parameter adjustment stage is completed and the gas path parameter is stable, according to the safe switching strategy, the high-voltage electrostatic control module is controlled to adjust the electrostatic parameter from the preset intermediate safe value or zero value to the second target steady-state value corresponding to the Nth process task.

[0082] Specifically, the first parameter adjustment stage focuses on the safe removal of the electrostatic parameter; the second parameter adjustment stage focuses on the reconstruction of the gas path parameter; and the third parameter adjustment stage focuses on the safe reconstruction of the electrostatic parameter. The preset intermediate safe value: a voltage value between the working high voltage and zero value, for example, 5kV or 10kV. Its role is to serve as a safe buffer zone. In some fine process switching, reducing the high voltage to the intermediate safe value instead of zero value can reduce the energy loss and time delay caused by completely turning off and turning on the high voltage, while still ensuring sufficient safety margin for gas path adjustment. Zero value is a complete safe state. First steady-state value, second steady-state value, first target steady-state value, second target steady-state value: steady-state value refers to the stable value that a parameter should maintain during the execution of a process task. The first refers to the electrostatic parameter, and the second refers to the gas path parameter. For example, the first steady-state value of the N-1th task may be -80kV (electrostatic high voltage), and the second steady-state value may be the powder feeding gas pressure 0.4MPa. The first target steady-state value of the Nth task is the new powder feeding gas pressure 0.25MPa, and the second target steady-state value is the new electrostatic high voltage -70kV.

[0083] Step implementation description: performing the first parameter adjustment stage (electrostatic safe removal): when the main control unit decides to switch from task N-1 to task N, it first checks the safe switching strategy of both (especially task N). The strategy indicates whether to adjust the electrostatic high voltage to zero value or a certain preset intermediate safe value (for example, when switching from large flow to small flow, it may only need to be reduced to the intermediate safe value). Then, the controller sends instructions to the high-voltage electrostatic control module, instructing it to smoothly reduce the output voltage from the current -80kV (first steady-state value) to 0kV or -10kV (preset intermediate safe value) according to the slope (such as 2kV / ms) specified by the strategy. The completion condition of this stage is that the high-voltage module feedbacks that its output has reached the target value.

[0084] Performing the second parameter adjustment phase (gas circuit reestablishment): After confirming that the high voltage has been safely reduced, the controller initiates the gas circuit switching according to the strategy. It resolves the first target steady state value of task N (i.e. the new gas circuit parameter set) and commands the actuators in the gas circuit control module (e.g. proportional valves, flow controllers) to gradually adjust the parameters such as powder feeding gas, atomizing gas, etc. from the state of task N-1 (second steady state value) to the new set value. This process can be simultaneous adjustment of multiple gas circuit sub-parameters or adjustment in a specific order.

[0085] Performing the third parameter adjustment phase (electrostatic safety reestablishment): The controller continuously monitors the gas circuit parameters and confirms through sensor feedback that they have stabilized within an acceptable fluctuation range around the first target steady state value. Once the gas circuit parameters are confirmed to be stable, the controller instructs the high voltage electrostatic control module to adjust the voltage from a pre-set intermediate safety value or zero value to the second target steady state value required by task N (e.g. -70kV) according to a rising slope that can be different from the descending slope.

[0086] In a preferred embodiment, in the first parameter adjustment phase and / or the third parameter adjustment phase, the process of controlling the high voltage electrostatic control module to adjust the electrostatic parameter includes the following steps:

[0087] Obtaining the real-time load current of the high voltage electrostatic control module;

[0088] Based on the real-time load current and a pre-set safety current threshold, dynamically adjusting the adjustment rate of the electrostatic parameter;

[0089] Wherein, when the real-time load current exceeds the pre-set safety current threshold, the adjustment rate of the electrostatic parameter is reduced until the real-time load current falls within the pre-set safety current threshold.

[0090] Specifically, real-time load current: the real-time current value at the output end of the high voltage electrostatic control module (high voltage generator). It directly reflects the intensity of the spray gun corona discharge and whether there is abnormal discharge (such as spark discharge). This current value is usually measured by a high-precision sampling circuit inside the high voltage generator and fed back to the main control unit in real time through digital communication. Pre-set safety current threshold: a pre-set upper limit of current I_safe. It is a software threshold for process control, usually set to 120%-150% of the normal stable corona discharge current. For example, if the current is 50μA during normal spraying, I_safe can be set to 60-75μA.

[0091] Step implementation description: Real-time load current acquisition: After the high-voltage adjustment instruction is issued, the host unit reads the real-time load current I_real from the high-voltage electrostatic control module at a high frequency (for example, 1 thousand times per second) through the communication bus. Dynamic adjustment of adjustment rate: compare I_real with the preset safe current threshold I_safe: normal case (I_real ≤ I_safe): the controller continues to send voltage adjustment instructions according to the default adjustment rate (for example, 5kV / ms when reducing voltage, and 3kV / ms when increasing voltage) preset in the safe switching strategy. Abnormal case (I_real>I_safe): this indicates that there may be an unexpected corona enhancement or impending spark discharge during the adjustment process. The controller immediately intervenes to reduce the adjustment rate of the voltage. For example, the rate is reduced from 5kV / ms to 1kV / ms. The purpose of reducing the speed is to slow down the change of electric field intensity, giving a time window for the discharge phenomenon to subside, avoiding the further rise of I_real triggered by the hardware protection due to the adjustment too fast. Recovery and completion: the controller continues to monitor I_real after reducing the speed. Once I_real falls within I_safe, indicating that the abnormal risk is removed, the controller can gradually restore the adjustment rate to the default value or a slightly lower safe value to continue the voltage adjustment process. The whole process is adaptive, ensuring that the voltage rising or falling trajectory is always constrained within the safe current boundary.

[0092] In a preferred embodiment, the adjusting the electrostatic parameter from the preset intermediate safe value or zero value to a second target steady-state value corresponding to the Nth process task comprises the following steps:

[0093] Starting voltage ramp-up, controlling the output voltage of the high-voltage electrostatic control module to increase from the intermediate safe value or zero value at a first increasing rate;

[0094] Monitoring the output current rate of change of the high-voltage electrostatic control module in real time during the voltage ramp-up process;

[0095] When the monitored output current rate of change exceeds a preset first threshold value representing the stable establishment of corona discharge, the actual establishment point of the electrostatic field is determined, and the actual voltage value at this time is recorded as the basic working point voltage;

[0096] Calculating the voltage difference value based on the basic working point voltage and the second target steady-state value;

[0097] According to the voltage difference value, adjusting the output voltage from the basic working point voltage to the second target steady-state value at a second increasing rate less than the first increasing rate.

[0098] Specifically, the quick exploration is initiated: the controller commands the high voltage generator to start raising the output voltage from 0 kV at a fast first ramp rate (e.g. 5 kV / ms). The discharge characteristics are monitored in real time: during the voltage ramping, the controller not only monitors the current value, but more importantly, it calculates the output current rate of change (dl / dt) in real time. At very low voltage, the current is almost 0, and dl / dt is close to 0. As the voltage approaches the inception point, ionization starts to occur in the air, and the current will start to appear and accelerate, and dl / dt will significantly increase. The actual inception point is determined: the controller continuously compares the calculated dl / dt with a first threshold value. Once dl / dt exceeds the threshold value, the system immediately captures the current output voltage value and records it as the base working point voltage (V_base). This marks that the threshold voltage at which the effective electrostatic field is actually established in this particular environment has been found. The remaining stroke is calculated: the controller reads the second target steady-state value (V_target) of the Nth task, and calculates the voltage difference AV = V_target - V_base. The precise positioning is performed: the controller switches the ramp rate of the high voltage generator to a slower second ramp rate. Then it instructs the high voltage generator to smoothly raise the voltage from V_base at this slower rate, and finally reach V_target. The slow ramping ensures that the electric field can be smoothly enhanced when approaching the target voltage, avoiding overshoot or oscillation, and making the powder adsorption force smoothly transition to the set value.

[0099] In a preferred embodiment, in the second parameter adjustment phase, the process of controlling the gas path control module to adjust the gas path parameter comprises the following steps:

[0100] at least one state parameter indicative of the powder delivery stability is acquired in real time;

[0101] it is determined whether the state parameter has reached a target stable range associated with the Nth process task;

[0102] if not, the current gas path control instruction is maintained and the monitoring continues; if yes, it is determined that the second parameter adjustment phase is complete, and a trigger signal is generated to start the third parameter adjustment phase;

[0103] The state parameter includes the instantaneous fluctuation value of the powder flow, the gas pressure change gradient in the powder feeding pipe, or the powder cloud concentration indirectly measured by the sensor.

[0104] Specifically, the state parameters characterizing the powder delivery stability: the physical quantities that can directly or indirectly reflect whether the powder-air two-phase flow in the pipe from the powder supply tank to the spray gun outlet reaches a stable and uniform delivery state. Including but not limited to the following parameters: powder flow instantaneous fluctuation value: measured in real time by a solid mass flow meter installed in the powder delivery pipe, calculate the standard deviation or peak-to-peak value of the flow data in a short time (such as a 100 millisecond window), the smaller the fluctuation value, the more stable. The air pressure change gradient in the powder delivery pipe: install a high-response pressure sensor on the powder delivery air pipe to monitor the rate of change of its pressure value over time (dP / dt). When the powder flow is stable, the air pressure fluctuation is minimal, and dP / dt is close to zero. The powder cloud concentration measured indirectly by the sensor: for example, install an optical sensor (such as a laser diffraction instrument) or an electric charge sensor near the gun mouth, and infer the concentration uniformity of the powder cloud by detecting the scattered light intensity or space charge. For the above state parameters, a stable qualified interval is preset for the Nth process task. For example, for the powder flow, the target stable range can be that the instantaneous fluctuation value is less than ±3% of the set value; for the air pressure gradient, it can be |dP / dt|<0.01 MPa / s. This range is stored in the process database and associated with the task ID.

[0105] Step implementation description:

[0106] Real-time acquisition of state parameters: after the controller issues air path parameter adjustment instructions, the corresponding sensors (flow meters, pressure sensors, concentration sensors) start high-frequency work. The main control unit continuously reads the raw data of these sensors through the data acquisition module (such as an analog input module or a special communication interface).

[0107] Data processing and feature extraction: the main control unit processes the read raw data in real time. For flow data, calculate its fluctuation value in a sliding time window; for pressure data, calculate its numerical difference to get the change gradient; for optical or electrical signals, convert them into powder concentration estimates and their stability indicators through calibration algorithms.

[0108] Stability judgment: the controller calls the target stable range associated with the current task N. It compares the real-time calculated state parameter value with this range. For example, whether the current flow fluctuation value 2.5% is less than the upper limit of the target stable range 3%.

[0109] Decision and trigger: if no (unstable): the controller keeps the current gas path control command unchanged (i.e. keeps the current valve opening, etc.), and continues to monitor. It will not rashly enter the next step. If yes (stable): the controller determines that the second parameter adjustment phase is formally completed. Then, it internally generates a trigger signal (such as setting a flag bit to TRUE, or calling a function to start high pressure reconstruction). This signal is a bridge connecting the key actions of gas path adjustment completion and high pressure reconstruction start.

[0110] In a preferred embodiment, the process database is established by the following method:

[0111] Select a reference process task as the target process task;

[0112] Control the device to run with the spraying process parameter set of the reference process task, and keep the gas path parameters and electrostatic parameters stable;

[0113] During stable operation, a series of pre-set parameter disturbances of different types are applied to the gas path control module and / or the high-voltage electrostatic control module, and the changes in the spraying quality indicators are monitored in real time;

[0114] Based on the response relationship between the parameter disturbances and the changes in the spraying quality indicators, a multi-parameter sensitivity model representing the stability of the reference process task is constructed;

[0115] Based on the multi-parameter sensitivity model, a corresponding safety switching strategy for the reference process task is generated; wherein the coordinated action sequence and time relationship of the gas path parameters and electrostatic parameters specified in the safety switching strategy are configured to actively avoid or compensate for the high sensitivity coupling relationship identified in the multi-parameter sensitivity model during the switching process;

[0116] The reference process task, its spraying process parameter set, its corresponding multi-parameter sensitivity model and safety switching strategy are associated to obtain the process database.

[0117] Specifically, the reference process task refers to a standard spraying task that has been fully verified, the process parameters (gas path, electrostatic) are known, and can produce qualified coatings, which is the starting point for modeling and analysis. For example, using a certain type of powder, under standard temperature and humidity, spraying a standard test plate to a certain film thickness.

[0118] Specifically, a representative reference task is selected: an operator or the system selects a representative reference task. The control device runs with its full set of spray process parameters, and through closed-loop control, keeps its gas circuit and electrostatic parameters highly stable, entering ideal steady state. Apply active disturbance and monitor: while keeping other conditions unchanged, the system, according to the preset program, orderly issues fine-tuning instructions to the gas circuit control module and / or the high-voltage electrostatic control module, applying a series of parameter disturbances. For example, first increase the atomizing gas pressure by 5% alone, monitor the change in the quality index; then restore it, and then reduce the output voltage by 3%, monitor the change; then try to increase the atomizing gas pressure by 5% while reducing the powder feeding gas pressure by 2%, monitor the change. During and after each disturbance, the system monitors the transient response and steady-state deviation of the spray quality index in real time through the sensors. Build a sensitivity model: the system (or the connected host computer software) collects all parameter disturbance patterns, amplitudes, and corresponding spray quality index change data. Using system identification, regression analysis, or machine learning algorithms, a multi-parameter sensitivity model is built to quantitatively describe the mapping relationship between the parameter space and the quality space. The model can answer questions such as how the film thickness uniformity will change if the atomizing gas pressure changes by 1%, and what is the best compensation amount of the powder feeding gas flow when the high voltage is changed, etc. Generate a safe switching strategy: based on the built model, the system automatically or assists in generating a safe switching strategy for the reference task. The core of the generation logic is to actively avoid or compensate for high-sensitivity coupling relationships. For example, if the model identifies that during the process of reducing the high voltage from 70kV to 50kV, if the powder feeding gas flow is increased at the same time, it will cause the powder concentration to fluctuate sharply, then the generated strategy will clearly stipulate that: when switching, the high voltage must be completely reduced to a safe value and maintained, and only after the high voltage is stable, the powder feeding gas flow can be adjusted. The sequence and time relationship of the coordinated actions in the strategy are directly derived from the understanding and transformation of the physical limitations revealed by the model. Correlation storage: finally, the name or ID of this reference process task, its spray process parameter set, its multi-parameter sensitivity model, and the safe switching strategy derived therefrom are stored as a data package in the process database. This makes each task record in the database contain the parameters of how to do it, and the deep knowledge of why to do it and how to safely switch.

[0119] In a preferred embodiment, after the second parameter adjustment phase is determined to be complete and the third parameter adjustment phase is initiated, before the step of performing the start voltage ramp-up is executed, the following steps are further included:

[0120] Obtaining first coordination state information characterizing the actual coordination state between the electric field intensity at the current spray gun outlet and the powder-air flow field pattern;

[0121] Based on the first coordination state information, evaluating the matching degree between it and the expected theoretical coordination state of the Nth process task;

[0122] generate at least one calibration parameter according to the matching degree when the matching degree is lower than a preset standard;

[0123] adjust execution parameters or execution timing of the third parameter adjustment phase based on the calibration parameter.

[0124] Specifically, the dynamic synergistic calibration phase: This is an intelligent fine-tuning link inserted between the second and third parameter adjustment phases. It does not change the final target values of the gas path and electrostatic, but fine-tunes the coupling point of the two in the switching timing, ensuring that the starting moment of high-voltage reconstruction is optimally matched with the current actual flow field. First synergistic state information: A comprehensive state description quantity, used to quantify the real-time matching between the electric field intensity distribution at the outlet of the spray gun and the powder-air flow field (concentration, velocity, morphology) distribution. It is an index obtained by fusing multiple sensor signals. Theoretical synergistic state: According to the parameter set of the Nth process task (such as the target atomizing gas pressure, powder type, target voltage), combined with aerodynamics and electrostatics principles, the optimal matching relationship that the electric field and flow field should present under ideal conditions is expected or simulated. It can be a pre-stored reference pattern or a set of expected characteristic values. Calibration parameter: When the matching degree is insufficient, the system calculates the instruction parameters for fine-tuning the subsequent high-voltage reconstruction process. It may include: adjustment amount of execution timing (for example, delay the start of high-voltage reconstruction by Δt milliseconds), or adjustment amount of execution parameters (for example, fine-tune the first rising rate from 5 kV / ms to 4.5 kV / ms).

[0125] Step implementation description: In the window period after the second parameter adjustment phase is determined to be completed, the trigger signal has been issued, but the voltage ramp-up has not yet been executed, the system initiates a collaborative state evaluation. This is usually achieved by sending a calibration high voltage signal and collecting multi-physical field signals, and finally fusing to obtain a first collaborative state information C_actual representing the current actual gas-electricity collaborative state. The system calls the theoretical collaborative state C_theory corresponding to the Nth process task from the process database. Through a pre-defined algorithm (such as calculating the cosine similarity of the feature vector, or comparing the root mean square error of the key feature parameters), the matching degree M between C_actual and C_theory is calculated. The system compares the matching degree M with a pre-set standard M_threshold (for example, 0.85). If M ≥ M_threshold, it is considered that the current collaborative state is good and no calibration is needed, and the subsequent process is executed according to the original plan. If M < M_threshold, it is considered that there is an optimal deviation. The system generates one or more calibration parameters according to the size of M and the specific pattern of the difference between C_actual and C_theory. For example, if analysis finds that the current flow field diffusion is slightly faster than expected (the powder cloud is relatively sparse), a timing calibration parameter may be generated to delay the voltage ramp-up start by 10 ms, allowing the flow field to stabilize again; if it is found that the electric field distribution is slightly uneven, a parameter calibration parameter may be generated to reduce the first rising rate by 15%, so that the electric field is established more gently. The system adjusts the execution parameters or execution timing of the subsequent third parameter adjustment phase. For example, the original high voltage start command is delayed by a specified delay time, or the adjusted rising rate parameter is sent to the high voltage generator.

[0126] In a preferred embodiment, the first collaborative state information representing the actual collaborative state between the electric field intensity at the outlet of the spray gun and the powder-air flow field pattern is obtained by the following steps:

[0127] Sending a control instruction to the high-voltage electrostatic control module to output a calibration high-voltage signal lower than the corona onset voltage threshold;

[0128] Synchronously collecting a first physical quantity signal reflecting the instantaneous electric field distribution and a second physical quantity signal reflecting the instantaneous flow field distribution during the duration of the calibration high-voltage signal;

[0129] Fusing the first physical quantity signal and the second physical quantity signal to obtain the first collaborative state information.

[0130] Specifically, calibration high voltage signal: an AC or DC high voltage signal with precisely controlled amplitude, far below the normal spraying corona onset voltage. Its typical value is 1 kV to 5 kV, the purpose is to establish a weak detection electric field at the gun nozzle under the premise of not triggering corona discharge and not interfering with the normal delivery of powder. This electric field itself is not enough to attract powder, but it is enough to be detected by a high-sensitivity sensor. Corona onset voltage threshold: refers to the minimum voltage value that can trigger corona discharge under the current environmental, gun type, and powder conditions. The amplitude of the calibration high voltage signal must be lower than this threshold, usually 30%-50% of it. First physical quantity signal: a signal reflecting the spatial electric field distribution characteristics generated by the calibration high voltage signal. It is usually measured by a micro electric field probe array deployed around the outlet of the spray gun, and the output signal reflects the intensity, uniformity, symmetry, etc. of the electric field. Second physical quantity signal: a signal reflecting the current (not disturbed by high voltage) powder-air flow field distribution characteristics. It is usually measured by an optical imaging system (such as a high-speed camera with backlight) or a phase Doppler particle analyzer (PDPA), and the output signal can be image sequences, particle velocity / concentration distribution data, etc.

[0131] Step implementation description: The master unit sends a special instruction to the high-voltage electrostatic control module, instructing it to temporarily switch to calibration mode and output a calibration high-voltage signal with constant amplitude and fixed duration (e.g. 50 milliseconds), such as a 3kV DC negative voltage. The instruction ensures that the voltage is strictly below the real-time estimated corona onset voltage threshold. During the entire period of calibration signal output, the system performs high-speed synchronous data acquisition: Electric field signal acquisition: The micro electric field sensor array arranged around the gun nozzle (usually non-contact) starts working, measuring the electric field intensity at each point in space in real time, forming the first physical quantity signal (may be a set of voltage time series data or an electric field distribution snapshot). Synchronously, the optical or particle analysis sensor takes a picture or scans the spray area at the outlet of the spray gun, obtaining data such as the morphology of the powder cloud, the concentration core position, the diffusion angle, etc., forming the second physical quantity signal (may be an image stream or data stream). Signal fusion processing: The collected raw signals are sent to the processing unit (which can be the master unit or a dedicated processor). The processing process includes: Time and space alignment: Ensure that the electric field and flow field data strictly correspond in time and space coordinates. Feature extraction: Extract features such as equipotential line distribution, maximum field strength position from the electric field signal; Extract features such as powder cloud contour, concentration centroid, principal axis direction from the flow field signal. Correlation analysis: Calculate the spatial relationship between the extracted electric field features and flow field features. For example, calculate the angle a between the direction of the maximum gradient of the electric field and the direction of the main axis of the powder cloud; Calculate the Euclidean distance d between the peak value point of the electric field strength and the concentration centroid of the powder; Evaluate whether the symmetry of the electric field distribution is consistent with the symmetry of the flow field distribution. Generate synergy state information: Combine the results of the above correlation analysis (such as angle a, distance d, symmetry score, etc.) into a structured data set, which is the first synergy state information. This information quantitatively describes the matching degree between the way the electric field is prepared to be applied and the state of the actual powder flow waiting to be applied in terms of spatial form at the current time.

[0132] In a preferred embodiment, the first threshold value is a dynamic threshold value retrieved from the process database based on identification information of the Nth process task; the dynamic threshold value is a current change rate threshold value determined according to the response relationship between the parameter disturbance and the change of the spray quality index in the process of constructing a multi-parameter sensitivity model associated with the Nth process task.

[0133] Specifically, threshold determination experiment: when building a multi-parameter sensitivity model for a certain process task (e.g. task X), a series of experiments specifically for the high-voltage establishment process will be carried out. The system raises the voltage from zero to the target value at different rates under stable gas path conditions, while simultaneously collecting the complete waveform of the output current rate of change (dI / dt) at high speed, and recording the spraying results (such as initial deposition uniformity) synchronously. Data analysis and correlation: analysts or algorithms analyze these data to find the correlation between dI / dt characteristics and the initial quality of spraying. The goal is to find a current rate of change threshold Threshold_X, so that when dI / dt first exceeds Threshold_X, it corresponds to the moment when the corona discharge enters a stable and effective state, and at this critical point, the best initial coating quality can be achieved. This threshold value can be determined by statistical methods (such as inflection point detection) or correlation analysis with quality indicators. Task-related storage: the determined Threshold_X is stored as a dynamic threshold specific to this process task, and is associated with the ID of task X, parameter set, sensitivity model, and safety switching strategy, and is stored in the process database. When executing online requires switching to task X, during the voltage ramp-up process, the system does not use a general threshold value, but based on the identification information of the Nth process task (i.e. the ID of task X), it retrieves its dedicated dynamic threshold Threshold_X from the process database in real time, and uses it as the first threshold for real-time judgment.

[0134] In a preferred embodiment, the following steps are further included:

[0135] If the output current rate of change is monitored to exceed a preset second threshold value before the output voltage reaches the base working point voltage, it is determined to be an abnormal discharge event, and the following operations are performed:

[0136] suspend the voltage ramp-up;

[0137] control the high-voltage electrostatic control module to lower the output voltage to a fault safety voltage below the intermediate safety value and maintain it for a first time period;

[0138] after the first time period ends, the step of starting the voltage ramp-up is re-executed;

[0139] wherein the second threshold value is greater than the first threshold value and is related to the powder type and environmental humidity information associated with the Nth process task.

[0140] Specifically, during the voltage ramp-up, the system monitors the output current rate of change and compares it to a first threshold value, while also comparing it in real-time to a second, higher threshold value, Threshold_spark. If the system monitors a momentary output current rate of change that exceeds the second threshold value, Threshold_spark, before the output voltage reaches the base operating point voltage (i.e., a normal corona is determined to be established), then an abnormal discharge event (spark discharge) is immediately determined. This is a high-priority fault signal. The system immediately aborts the ongoing voltage ramp-up command. At the same time, the high voltage electrostatic control module is commanded to reduce the output voltage to a very low fault safe voltage (e.g., 1 kV) in the shortest time possible (e.g., 1 millisecond). The high voltage module maintains the output at the fault safe voltage for a first time period (e.g., 500 milliseconds). This period of silence is critical for the physical recovery of the system. After the first time period, the system re-executes the steps to initiate a voltage ramp-up, attempting to re-establish the high voltage. The number of retries can be capped. The setting of the second threshold value is related to the powder type associated with the Nth process task and the ambient humidity information. For example, for high resistivity powders or in dry environments, it is more likely that charge will build up to cause a violent spark, so the second threshold value can be set relatively low (more sensitive); conversely, it can be set higher to avoid false positives.

[0141] The principles and implementation manners of the present application are described herein by using specific examples, and the above examples are only used to help understand the method and core idea of the present application. The above description is only the preferred implementation manner of the present application, and it should be pointed out that, due to the limited expression of the text, there are infinite specific structures in the objective world, and for ordinary skilled persons in the technical field, a number of improvements, refinements or changes can be made without departing from the principles of the present application, and the above technical features can also be combined in an appropriate manner; these improvements, refinements, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, shall be regarded as the protection scope of the present application.

Claims

1. An electrostatic spraying safety control method based on process task scheduling, applied to an electrostatic spraying control device, the device comprising a master control unit, a storage module, an air path control module connected with the master control unit, and a high-voltage electrostatic control module; characterized in that, The method includes the following steps: Receive a task execution sequence that includes at least two process tasks; Based on the Nth process task to be executed, call the process database to obtain the set of spraying process parameters associated with it, and the corresponding safety switching strategy. If N=1, then the air path control module and the high voltage electrostatic control module are directly controlled to enter the parameter state represented by the spraying process parameter set associated with the first process task. If N>1, the device is controlled to perform a switching process according to the safety switching strategy corresponding to the (N-1)th process task and the Nth process task respectively; after switching, the gas path control module and the high voltage electrostatic control module are controlled to operate under the parameter state characterized by the spraying process parameter set associated with the Nth process task. Repeat the above steps until all process tasks in the task execution sequence have been completed. The spraying process parameter set includes gas path parameters executed by the gas path control module and electrostatic parameters executed by the high-voltage electrostatic control module; the safety switching strategy specifies the sequence and timing of the coordinated actions of the gas path parameters and the electrostatic parameters during state transitions. The secure handover strategy includes: Exit correlation rules: Define how the device should safely and orderly exit from its current steady-state parameters when the process task is the source task to be switched out, including the order and rate of removal of electrostatic parameters and the transition method of gas path parameters; The entry correlation rule defines how the device should safely and orderly enter its set steady-state parameters from a certain intermediate or safe state when the process task is the target task to be switched in, including the establishment order and stability judgment of gas path parameters, and the reconstruction order and rate of electrostatic parameters. The switching process includes: The first sub-process is executed according to the exit association rule corresponding to the (N-1)th process task; The second sub-process is executed according to the entry association rule corresponding to the Nth process task; The sequence and timing of coordinated actions of the gas path parameters and electrostatic parameters during state transitions, as specified in the safety switching strategy, are generated based on a multi-parameter sensitivity model associated with the process task in the process database. This model is configured to actively avoid or compensate for high-sensitivity coupling relationships identified in the multi-parameter sensitivity model during the switching process.

2. The process task schedule based electrostatic spray painting safety control method of claim 1, wherein: The control device executes the switching process according to the safety switching strategy corresponding to the (N-1)th process task and the Nth process task, including the following steps: Execute the first parameter adjustment stage: According to the safety switching strategy, control the high voltage electrostatic control module to adjust the electrostatic parameter from the first steady-state value corresponding to the N-1th process task to a preset intermediate safety value or zero value; Execute the second parameter adjustment phase: After the first parameter adjustment phase is completed, according to the safety switching strategy, control the gas path control module to adjust the gas path parameter from the second steady-state value corresponding to the N-1th process task to the first target steady-state value corresponding to the Nth process task; performing a third parameter adjustment stage: after the second parameter adjustment stage is completed and the gas path parameters are stable, according to the safety switching strategy, the high-voltage electrostatic control module is controlled to adjust the electrostatic parameter from the preset intermediate safety value or zero value to a second target steady-state value corresponding to the Nth process task.

3. The process task schedule based electrostatic spray painting safety control method of claim 2, wherein: In the first parameter adjustment stage and / or the third parameter adjustment stage, the process of controlling the high-voltage electrostatic control module to adjust the electrostatic parameter includes the following steps: acquiring the real-time load current of the high-voltage electrostatic control module; based on the real-time load current and a preset safety current threshold, dynamically adjusting the adjustment rate of the electrostatic parameter; wherein when the real-time load current exceeds the preset safety current threshold, the adjustment rate of the electrostatic parameter is reduced until the real-time load current falls within the preset safety current threshold.

4. The process task schedule based electrostatic spray safety control method of claim 2, wherein: The step of adjusting the electrostatic parameter from the preset intermediate safety value or zero value to the second target steady-state value corresponding to the Nth process task includes the following steps: starting a voltage ramp-up, controlling the output voltage of the high-voltage electrostatic control module to start from the intermediate safety value or zero value and increase at a first rising rate; during the voltage ramp-up process, the output current change rate of the high-voltage electrostatic control module is monitored in real time; when the output current change rate is monitored to exceed a preset first threshold value representing the stable establishment of corona discharge, the actual establishment point of the electrostatic field is determined, and the actual voltage value at this time is recorded as the basic working point voltage; based on the basic working point voltage and the second target steady-state value, a voltage difference value is calculated; based on the voltage difference value, the output voltage is adjusted from the basic working point voltage to the second target steady-state value at a second rising rate smaller than the first rising rate.

5. The process task schedule based electrostatic spray painting safety control method of claim 2, wherein: In the second parameter adjustment stage, the process of controlling the gas path control module to adjust the gas path parameter includes the following steps: real-time acquisition of at least one state parameter representing the stability of powder delivery; determining whether the state parameter has reached a target stable range associated with the Nth process task; if not, maintaining the current gas path control instruction and continuing to monitor; if yes, determining that the second parameter adjustment stage is completed, and generating a trigger signal to start the third parameter adjustment stage; wherein the state parameter includes a powder flow instantaneous fluctuation value, a gas pressure change gradient in the powder feeding pipe, or a powder cloud concentration indirectly measured by a sensor.

6. The process task schedule based electrostatic spray painting safety control method of claim 4, wherein: The process database is established by the following method: selecting a reference process task as a target process task; controlling the device to run with the spraying process parameter set of the reference process task, and keeping the gas path parameter and the electrostatic parameter stable; during stable operation, a series of preset parameter disturbances of different types are applied to the gas path control module and / or the high-voltage electrostatic control module, and the change of the spraying quality index is monitored in real time; based on the response relationship between the parameter disturbance and the change of the spraying quality index, a multi-parameter sensitivity model representing the stability of the reference process task is constructed; Based on the multi-parameter sensitivity model, a corresponding safe switching strategy is generated for the benchmark process task; wherein the coordinated action sequence and time relationship of the gas path parameters and electrostatic parameters in the state transition specified in the safe switching strategy is configured to actively avoid or compensate for the high sensitivity coupling relationship identified in the multi-parameter sensitivity model in the switching process; The process database is obtained by associating the benchmark process task, its spraying process parameter set, its corresponding multi-parameter sensitivity model and safe switching strategy.

7. The process task schedule based electrostatic spray painting safety control method of claim 4, wherein: After the second parameter adjustment phase is determined to be completed and the third parameter adjustment phase is started, before the step of performing the starting voltage ramp-up, the following steps are further included: Obtain first coordination state information representing the actual coordination state between the electric field intensity at the current spray gun outlet and the powder-air flow field pattern; Based on the first coordination state information, evaluate the matching degree between it and the expected theoretical coordination state of the Nth process task; When the matching degree is lower than a preset standard, generate at least one calibration parameter according to the matching degree; Based on the calibration parameter, adjust the execution parameter or execution timing of the third parameter adjustment phase.

8. The process task schedule based electrostatic spray safety control method of claim 7, wherein: The first coordination state information representing the actual coordination state between the electric field intensity at the current spray gun outlet and the powder-air flow field pattern is obtained by the following steps: Send a control instruction to the high-voltage electrostatic control module to output a calibration high-voltage signal lower than the corona onset voltage threshold; During the duration of the calibration high-voltage signal, synchronously collect a first physical quantity signal reflecting the instantaneous electric field distribution and a second physical quantity signal reflecting the instantaneous flow field distribution; Fuse the first physical quantity signal and the second physical quantity signal to obtain the first coordination state information.

9. The process task schedule based electrostatic spray safety control method of claim 6, wherein: The first threshold value is a dynamic threshold value retrieved from the process database based on the identification information of the Nth process task; The dynamic threshold value is a current change rate threshold value determined according to the response relationship between the parameter disturbance and the spraying quality index change in the process of constructing the multi-parameter sensitivity model associated with the Nth process task.

10. The process task schedule based electrostatic spray painting safety control method of claim 4, wherein: Further comprising the following steps: If the output current change rate exceeds a preset second threshold value before the output voltage reaches the base operating point voltage, it is determined to be an abnormal discharge event, and the following operations are performed: Abort the voltage ramp-up; Control the high-voltage electrostatic control module to reduce the output voltage to a fault safety voltage lower than the intermediate safety value and maintain it for a first time period; After the first time period ends, the step of starting voltage ramp-up is re-executed; Wherein the second threshold value is greater than the first threshold value and is related to the powder type and environmental humidity information associated with the Nth process task.

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