A precise on-off control method and system for a drying device

Abstract

The present application provides a precise on-off control method and system for a drying device, which relates to the technical field of vehicle body drying. The method includes the following steps: obtaining the predicted spraying end time of the target vehicle; the target vehicle is the first vehicle in the current processing batch to complete the spraying process, and the spraying process is the previous production process of the drying process; determining the delivery window; wherein, the end point of the delivery window is the delivery time minus the necessary processing duration of the subsequent process of the drying process, and the starting point of the delivery window is the predicted spraying end time; obtaining the off-peak electricity price period, and determining whether there is an overlapping period between the off-peak electricity price period and the delivery window; if so, predicting the total drying duration of the drying process of the current processing batch; if the overlapping period is equal to the total drying duration, taking the starting point of the overlapping period as the first drying room opening time, and controlling the drying room to start up at the first drying room opening time. This solution can achieve the dual-objective optimization of the economy and timeliness of the operation of the drying device.

Description

Technical Field

[0001] This application relates to the technical field of vehicle body drying, and particularly to a precise on-off control method and system for drying equipment. Background Art

[0002] In the field of industrial painting production, the drying process is a key link in the painting process chain, and its equipment control directly affects production energy consumption and delivery timeliness. Traditional control methods for drying equipment mostly use a fixed production scheduling mode for on-off operations, which have two limitations in practical applications: the fixed production scheduling mode may cause the drying equipment to start prematurely, resulting in ineffective standby energy consumption, or being forced to operate during peak electricity price periods to catch up with delivery deadlines; on the other hand, conventional methods do not adequately consider the overall process connection of batch-processed vehicles, especially in multi-process collaborative scenarios, it is difficult to accurately balance the requirements of energy cost control and production rhythm matching. Summary of the Invention

[0003] In view of the above-mentioned defects or deficiencies in the prior art, this application aims to provide a precise on-off control method and system for drying equipment to achieve the dual-objective optimization of the economy and timeliness of the operation of the drying equipment.

[0004] In a first aspect, this application proposes a precise on-off control method for drying equipment, including the following steps:

[0005] Obtain the predicted end time of spraying for the target vehicle; the target vehicle is the first vehicle in the current processing batch to complete the spraying process, and the spraying process is the previous production process of the drying process;

[0006] Determine the delivery window; wherein, the end point of the delivery window is the delivery time minus the necessary processing duration of the subsequent process of the drying process, and the start point of the delivery window is the predicted end time of spraying; the delivery time is the time when the vehicles in the current processing batch are delivered to customers;

[0007] Obtain the off-peak electricity price period and determine whether there is an overlapping period between the off-peak electricity price period and the delivery window;

[0008] If so, predict the total drying duration of the drying process for the current processing batch;

[0009] If the overlapping period is equal to the total drying duration, use the start point of the overlapping period as the first drying room opening time to control the startup of the drying room.

[0010] According to the technical solution provided by the embodiment of this application, the step of predicting the total drying duration of the drying process for the current processing batch further includes the following steps:

[0011] Obtain the target paint film parameters of the target vehicle, the ambient temperature and ambient humidity of the drying oven at the predicted end time of spraying; the target paint film parameters include paint film thickness and coating curing threshold;

[0012] Based on the paint film thickness and the ambient temperature, calculate the preheating stage duration of the paint film of a single vehicle;

[0013] According to the coating curing threshold and ambient humidity, calculate the constant temperature curing stage duration of the paint film of a single vehicle;

[0014] Perform a weighted sum of the preheating stage duration and the constant temperature curing stage duration to obtain the reference drying duration of a single vehicle; wherein, the preheating weight coefficient of the preheating stage duration and the constant temperature weight coefficient of the constant temperature curing stage duration are generated by inverse fitting through historical drying quality data;

[0015] Obtain the total number of vehicles in this processing batch and the time interval between adjacent vehicles entering the drying oven;

[0016] Multiply the reference drying duration by the total number of vehicles, and add the cumulative value of the time interval to obtain the total drying duration.

[0017] According to the technical solution provided in the embodiment of the present application, after predicting the total drying duration of the drying process of this processing batch, the following steps are further included:

[0018] If the overlapping period is greater than the total drying duration, select at least one candidate sub-period that satisfies the total drying duration constraint from the overlapping period;

[0019] Use the start point of the candidate sub-period as the second drying oven start time, and control the drying oven to start up at the second drying oven start time.

[0020] According to the technical solution provided in the embodiment of the present application, after selecting at least one candidate sub-period that satisfies the total drying duration constraint from the overlapping period, the following steps are further included:

[0021] Select the candidate sub-period with the longest time interval from the delivery window end point as the first candidate sub-period;

[0022] Use the start point of the first candidate sub-period as the third drying oven start time, and control the drying oven to start up at the third drying oven start time.

[0023] According to the technical solution provided in the embodiment of the present application, after selecting at least one candidate sub-period that satisfies the total drying duration constraint from the overlapping period, the following steps are further included:

[0024] Obtain the remaining heat maintenance duration of the drying room and the necessary temperature control requirement duration for subsequent processes; the remaining heat maintenance duration is the duration during which the temperature in the drying room does not drop below the minimum requirement temperature for subsequent processes after the drying room stops operating.

[0025] If the remaining heat maintenance duration is greater than or equal to the necessary temperature control requirement duration for subsequent processes, then select the candidate sub-period with the end point closest to the end point of the electricity price valley period as the second candidate sub-period.

[0026] Take the start point of the second candidate sub-period as the start time for starting the fourth drying room, and control the drying room to start up at the start time of the fourth drying room.

[0027] According to the technical solution provided in the embodiment of the present application, after predicting the total drying duration of the drying process for this processing batch, the following steps are further included:

[0028] If the overlapping period is less than the total drying duration, then calculate the remaining drying requirement duration, where the remaining drying requirement duration is the total drying duration minus the overlapping period.

[0029] Obtain the remaining heat temperature decay curve of the drying room, where the remaining heat temperature decay curve is a curve representing the temperature drop in the drying room over time after it stops operating.

[0030] Obtain the minimum requirement temperature curve for the remaining drying stage, which is generated according to the requirements of the paint film curing process and is used to define the minimum temperature limit for different drying stages.

[0031] Based on the remaining heat temperature decay curve and the minimum requirement temperature curve, calculate the effective temperature maintenance duration of the drying room after it stops operating, where the effective temperature maintenance duration is the maximum continuous duration during which the remaining heat temperature is not lower than the minimum requirement temperature curve.

[0032] If the following conditions are simultaneously met:

[0033] If the remaining drying requirement duration is less than or equal to the effective temperature maintenance duration, and the start point of the electricity price valley period, the overlapping period, and the sum of the remaining drying requirement duration are not later than the end point of the delivery window, then take the start point of the electricity price valley period as the start time for starting the fifth drying room and control the drying room to start up.

[0034] According to the technical solution provided in the embodiment of the present application, after taking the start point of the electricity price valley period as the start time for starting the fifth drying room and controlling the drying room to start up, the following steps are further included:

[0035] Obtain the end time of the total drying duration, where the end time is the time when the start time of the fifth drying room is added to the total drying duration.

[0036] Take the later of the end time of the valley electricity price period and the end time of the total drying duration as the first shutdown time, and control the drying room to shut down.

[0037] According to the technical solution provided by the embodiment of the present application, the following steps are further included:

[0038] Obtain the predicted spraying end time of each vehicle in this processing batch and the queuing sequence for entering the drying room.

[0039] Based on the queuing sequence, calculate the drying start time and drying end time of each vehicle.

[0040] If the drying end time of any vehicle is later than the end of the delivery window, trigger a scheduling adjustment warning.

[0041] According to the technical solution provided by the embodiment of the present application, the following steps are further included:

[0042] During the preset monitoring period before the drying room runs to the first shutdown time, obtain the actual drying progress of each vehicle in this processing batch and the current residual heat temperature decay curve of the drying room in real time.

[0043] Based on the actual drying progress, calculate the minimum required drying duration of the remaining vehicles.

[0044] If the minimum required drying duration is less than the difference between the first shutdown time and the current time, calculate the earliest shutdown time according to the minimum required drying duration of the remaining vehicles and the current residual heat temperature decay curve of the drying room.

[0045] Update the first shutdown time with the earliest shutdown time, and control the drying room to shut down at the updated time.

[0046] Among them, the earliest shutdown time needs to satisfy both:

[0047] The drying completion time of all remaining vehicles is not later than the end of the delivery window;

[0048] The residual heat temperature decay curve of the drying room after shutdown is not lower than the minimum required temperature curve of the corresponding stage of the remaining vehicles.

[0049] In a second aspect, the present application proposes a precise on-off control system for a drying device, which is used to implement the precise on-off control method of the drying device as described above, including:

[0050] A prediction module, the prediction module is configured to obtain the predicted spraying end time of the target vehicle; the target vehicle is the first vehicle in this processing batch to complete the spraying process, and the spraying process is the previous production process of the drying process;

[0051] The prediction module is further configured to determine a delivery window; wherein, the end point of the delivery window is the delivery time minus the necessary processing duration of the subsequent processes of the drying process, and the start point of the delivery window is the predicted spraying end time; the delivery time is the time when the vehicle of the current processing batch is delivered to the customer.

[0052] A collection module, the collection module is configured to obtain the off-peak electricity price period and determine whether there is an overlapping period between the off-peak electricity price period and the delivery window.

[0053] The prediction module is further configured to, if so, predict the total drying duration of the drying process of the current processing batch.

[0054] A control module, the control module is configured to, if the overlapping period is equal to the total drying duration, use the start point of the overlapping period as the first drying room start time to control the start of the drying room at the first drying room start time.

[0055] Compared with the prior art, the beneficial effects of the present application are as follows: Through the reverse derivation of the time positioning of the first vehicle completed spraying and the delivery window, the present application constructs an accurate time anchor point for process connection, ensuring that the start time of the drying process simultaneously meets the delivery time limit constraint and the requirement of maximizing equipment utilization rate; introducing an intelligent matching mechanism for electricity price periods, on the premise of ensuring that the total drying duration completely covers the off-peak electricity price period, making the equipment operation cycle coincide precisely with the low-price electricity period, reducing energy costs; by dynamically calculating the overlapping relationship between the total drying duration and the off-peak electricity price period, not only eliminating the equipment idling loss caused by traditional preheating in advance, but also avoiding the risk of electricity bill premium caused by process delay. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is a step flow chart of a precise on-off control method for a drying device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0057] The present application will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related invention, rather than limiting the invention. Additionally, it should be noted that for the sake of description, only parts related to the invention are shown in the drawings.

[0058] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the drawings and embodiments.

[0059] Embodiment 1

[0060] As mentioned in the background art, in view of the problems in the prior art, the present application proposes a precise on-off control method for a drying device, as Figure 1 shown, including the following steps:

[0061] S1. Obtain the predicted spraying end time of the target vehicle; the target vehicle is the first vehicle in this processing batch to complete the spraying process, and the spraying process is the previous production process of the drying process.

[0062] Specifically, obtain the vehicle model parameters, coating process of the target vehicle, and the average spraying duration of historical vehicles of the same type; collect the operating status of the spraying equipment, ambient temperature and humidity, and manual intervention events in real time; based on the multiple regression model, dynamically correct the historical average spraying duration to generate the predicted spraying end time.

[0063] Exemplarily, assume that in an automobile manufacturing factory, there are 6 vehicles in this processing batch that need to be sprayed and dried. According to the above method, the predicted spraying end time of the target vehicle is 18:00 on March 15, 2025.

[0064] S2. Determine the delivery window; wherein, the end point of the delivery window is the delivery time minus the necessary processing duration of the subsequent process of the drying process, and the start point of the delivery window is the predicted spraying end time; the delivery time is the time when the vehicles in this processing batch are delivered to the customer; the delivery window is a time interval.

[0065] Exemplarily, it is known that the delivery time of the vehicles in this processing batch is 12:00 on March 16, 2025, and the necessary processing duration of the subsequent processes (such as assembly, inspection, etc.) of the drying process is 4 hours. Then the end point of the delivery window is 08:00 on March 16, 2025, the start point is 18:00 on March 15, 2025, and the delivery window is 18:00 - 08:00.

[0066] S3. Obtain the off-peak electricity price period and determine whether there is an overlapping period between the off-peak electricity price period and the delivery window; specifically, the off-peak electricity price period is the time period with a lower electricity price in the power supply.

[0067] Exemplarily, it is learned from the power supplier that the local off-peak electricity price period is from 23:00 of the previous day to 07:00 of the next day. There is an overlapping period between the off-peak electricity price period and the delivery window, that is, 23:00 - 07:00.

[0068] S4. If so, predict the total drying duration of the drying process of this processing batch.

[0069] Further, in a preferred embodiment, predicting the total drying duration of the drying process of this processing batch further includes the following steps:

[0070] Obtain the target paint film parameters of the target vehicle, the ambient temperature and humidity in the drying room at the predicted spraying end time; the target paint film parameters include the paint film thickness and the coating curing threshold.

[0071] Calculate the preheating stage duration of the paint film for a single vehicle based on the paint film thickness and the ambient temperature;

[0072] Calculate the constant temperature curing stage duration of the paint film for a single vehicle according to the paint curing threshold and the ambient humidity;

[0073] Perform a weighted sum of the preheating stage duration and the constant temperature curing stage duration to obtain the benchmark drying duration for a single vehicle; wherein, the preheating weight coefficient of the preheating stage duration and the constant temperature weight coefficient of the constant temperature curing stage duration are generated by inverse fitting through historical drying quality data;

[0074] Obtain the total number of vehicles in this processing batch and the time interval between adjacent vehicles entering the drying oven;

[0075] Multiply the benchmark drying duration by the total number of vehicles, and add the cumulative value of the time interval to obtain the total drying duration.

[0076] Specifically, the paint film thickness can be measured by a paint film thickness gauge, and the ambient temperature and humidity in the drying oven can be obtained through a temperature and humidity sensor. Establish a preheating duration calculation model based on the paint film thickness and the ambient temperature. For example, according to experimental data, an empirical formula is obtained: preheating stage duration = (paint film thickness × coefficient 1) / (ambient temperature × coefficient 2), where coefficient 1 and coefficient 2 are obtained by fitting experimental data. Similarly, establish a constant temperature curing duration calculation model based on the paint curing threshold and the ambient humidity. For example, constant temperature curing stage duration = (paint curing threshold × coefficient 3) / (ambient humidity × coefficient 4), and coefficient 3 and coefficient 4 are obtained by fitting experimental data. Processing batch: A total of 6 sedans of the same model need to enter the drying oven for drying in sequence. Target vehicle parameters: Paint film thickness: 0.3 mm (measured in real time by a paint film thickness gauge) Paint curing threshold: 150 °C (defined in the paint technical manual) Drying oven environmental parameters: Ambient temperature: 25 °C Ambient humidity: 60% (monitored in real time by a temperature and humidity sensor), Experimental fitting coefficients (calibrated through historical experimental data): Preheating stage: coefficient 1 = 1.8, coefficient 2 = 0.04; Constant temperature curing stage: coefficient 3 = 0.05, coefficient 4 = 0.08; Weight coefficients (generated by inverse fitting): Preheating stage weight: 0.35; Constant temperature curing stage weight: 0.65. Based on the above data, the total drying duration is approximately 8 hours.

[0077] S5. If the overlapping period is equal to the total drying duration, then use the start point of the overlapping period as the first drying oven start time, and control the drying oven to start up at the first drying oven start time.

[0078] Exemplarily, since the overlapping period (8 hours) is equal to the total drying duration (8 hours) and this condition is met, then the first drying oven start time is 23:00 on March 15, 2025.

[0079] In a preferred embodiment, after predicting the total drying duration of the drying process for this processing batch, the following steps are further included:

[0080] If the overlapping period is greater than the total drying duration, select at least one candidate sub-period that meets the constraint of the total drying duration from the overlapping period;

[0081] Use the start point of the candidate sub-period as the opening time of the second drying chamber, and control the start-up of the drying chamber based on the opening time of the second drying chamber.

[0082] Exemplarily, it is known that the overlapping period is from 23:00 to 07:00, with a duration of 8 hours, and the total drying duration is assumed to be 6 hours. Since the overlapping period is greater than the total drying duration, candidate sub-periods are selected: The candidate sub-periods that meet the constraint of the total drying duration can be from 23:00 on March 15, 2025 to 05:00 on March 16, 2025, from 01:00 on March 16, 2025 to 07:00 on March 16, 2025, etc.; If the candidate sub-period from 23:00 on March 15, 2025 to 05:00 on March 16, 2025 is selected, then the opening time of the second drying chamber is 23:00 on March 15, 2025, and the start-up of the drying chamber is controlled.

[0083] Further, after selecting at least one candidate sub-period that meets the constraint of the total drying duration from the overlapping period, the following steps are further included:

[0084] Select the candidate sub-period with the longest time interval from the end point of the delivery window as the first candidate sub-period;

[0085] Use the start point of the first candidate sub-period as the opening time of the third drying chamber, and control the start-up of the drying chamber based on the opening time of the third drying chamber.

[0086] Exemplarily, candidate sub-period 1 is from 23:00 on March 15, 2025 to 05:00 on March 16, 2025, and the time interval from the end point of the delivery window (08:00 on March 16, 2025) is 3 hours; candidate sub-period 2 is from 01:00 on March 16, 2025 to 07:00 on March 16, 2025, and the time interval from the end point of the delivery window is 1 hour. So, candidate sub-period 1 is selected as the first candidate sub-period. Use 23:00 on March 15, 2025, the start point of the first candidate sub-period, as the opening time of the third drying chamber, and control the start-up of the drying chamber.

[0087] When there are multiple candidate sub - time periods to choose from in this embodiment, by selecting the time period with the longest time interval from the end point of the delivery window, more adjustment time is reserved for the subsequent production processes. This improves the flexibility and fault tolerance of the production plan and reduces the impact of the drying process on the subsequent processes.

[0088] Further, after selecting at least one candidate sub - time period that meets the total drying duration constraint from the overlapping time periods, the following steps are also included:

[0089] Obtain the remaining heat maintenance duration of the drying room and the necessary temperature control requirement duration of the subsequent process; the remaining heat maintenance duration is the duration during which the temperature of the drying room does not drop below the minimum required temperature of the subsequent process after the drying room stops.

[0090] If the remaining heat maintenance duration is greater than or equal to the necessary temperature control requirement duration of the subsequent process, select the candidate sub - time period whose end point is closest to the end point of the electricity price valley section as the second candidate sub - time period;

[0091] Use the start point of the second candidate sub - time period as the start time for turning on the fourth drying room, and control the drying room to start up based on the start time of the fourth drying room.

[0092] Specifically, obtain the remaining heat maintenance duration of the drying room through experiments or historical data statistics, and determine the necessary temperature control requirement duration from the process requirements of the subsequent process. Exemplarily, through experiments and historical data statistics, it is known that the remaining heat maintenance duration of the drying room is 3 hours, and the necessary temperature control requirement duration of the subsequent process is 2 hours. Since the remaining heat maintenance duration (3 hours) is greater than the necessary temperature control requirement duration of the subsequent process (2 hours), and the electricity price valley section is from 23:00 to 07:00, select the candidate sub - time period 2 whose end point is closest to the end point of the electricity price valley section as the second candidate sub - time period. Use the start point of the second candidate sub - time period, 01:00 on March 16, 2025, as the start time for turning on the fourth drying room, and control the drying room to start up.

[0093] This embodiment takes into account that when the remaining heat of the drying room can meet the temperature control requirements of the subsequent process, by selecting a suitable candidate sub - time period, the electricity price valley section is fully utilized for drying operations. On the premise of meeting the temperature control requirements of the subsequent process, the electricity price valley section is utilized to the maximum extent to reduce the electricity cost.

[0094] In a preferred embodiment, after predicting the total drying duration of the drying process of this processing batch, the following steps are also included:

[0095] If the overlapping time period is less than the total drying duration, calculate the remaining drying demand duration, and the remaining drying demand duration is the total drying duration minus the overlapping time period;

[0096] Obtain the remaining heat temperature decay curve of the drying room, and the remaining heat temperature decay curve is a curve representing the temperature drop of the drying room over time after it stops.

[0097] Obtain the lowest required temperature curve for the remaining drying stage. The lowest required temperature curve is generated according to the requirements of the paint film curing process and is used to define the lowest temperature limit for different drying stages.

[0098] Based on the waste heat temperature decay curve and the lowest required temperature curve, calculate the effective duration of temperature maintenance in the drying room after shutdown. The effective duration of temperature maintenance is the maximum continuous duration during which the waste heat temperature is not lower than the lowest required temperature curve.

[0099] If the following conditions are simultaneously met:

[0100] If the remaining drying required duration is less than or equal to the effective duration of temperature maintenance, and the start point of the electricity price valley period, the overlapping period, and the sum of the remaining drying required duration are not later than the end point of the delivery window, then use the start point of the electricity price valley period as the opening time of the fifth drying room and control the drying room to start up.

[0101] Exemplarily, assume that the total drying duration is 8 hours, the overlapping period is from 23:00 on March 15, 2025 to 05:00 on March 16, 2025, with a duration of 6 hours. Then the remaining drying required duration is 8 - 6 = 2 hours. The waste heat temperature decay curve of the drying room is obtained by fitting experimental data, and the lowest required temperature curve is drawn according to the requirements of the paint film curing process. By comparing the waste heat temperature decay curve and the lowest required temperature curve, the effective duration of temperature maintenance is obtained as 3 hours. The remaining drying required duration (2 hours) is less than the effective duration of temperature maintenance (3 hours), and the sum of the start point of the electricity price valley period (23:00 on March 15, 2025), the overlapping period (6 hours), and the remaining drying required duration (2 hours) (07:00 on March 16, 2025) is not later than the end point of the delivery window (08:00 on March 16, 2025). Then use 23:00 on March 15, 2025, the start point of the electricity price valley period, as the opening time of the fifth drying room and control the drying room to start up.

[0102] In this embodiment, when the overlapping period between the electricity price valley period and the delivery window is less than the total drying duration, by reasonably utilizing the waste heat of the drying room and the electricity price valley period, the optimization of the drying operation is realized. In the case of a short electricity price valley period, the start-up time of the drying room can still be reasonably arranged, the electricity consumption cost can be reduced, and the drying quality can be ensured at the same time.

[0103] In a preferred embodiment, after using the start point of the electricity price valley period as the opening time of the fifth drying room and controlling the drying room to start up, the following steps are further included:

[0104] Obtain the end time of the total drying duration. The end time is the time when the opening time of the fifth drying room is added to the total drying duration.

[0105] Take the later of the end time of the valley period of the electricity price and the end time of the total drying duration as the first shutdown time, and control the drying room to shut down.

[0106] Exemplarily, the start time of the fifth drying room is 23:00 on March 15, 2025, and the total drying duration is 8 hours. Then the end time of the total drying duration is 07:00 on March 16, 2025. The end time of the valley period of the electricity price is 07:00 on March 16, 2025, and the end time of the total drying duration is 07:00 on March 16, 2025. The two are the same, so the first shutdown time is 07:00 on March 16, 2025.

[0107] This embodiment can reasonably determine the shutdown time after determining the start time of the drying room, ensure the completion of the drying operation, and make full use of the valley period of the electricity price. Avoid shutting down too early or too late, ensure the drying quality, and reduce the electricity cost at the same time.

[0108] In a preferred embodiment, the following steps are further included:

[0109] Obtain the predicted spraying end time of each vehicle in this processing batch and the queuing sequence for entering the drying room;

[0110] Based on the queuing sequence, calculate the drying start time and drying end time of each vehicle;

[0111] If the drying end time of any vehicle is later than the end of the delivery window, trigger a scheduling adjustment alarm.

[0112] Exemplarily, obtain the predicted painting end time and the queuing sequence for entering the drying oven of 20 vehicles in this processing batch from the production planning and forecasting system. For example, the predicted painting end time of the first vehicle is 18:00 on March 15, 2025, and that of the second vehicle is 18:30 on March 15, 2025, etc. Assume that the drying duration of the first vehicle is 4 hours, its drying start time is 18:00 on March 15, 2025, and the drying end time is 22:00 on March 15, 2025. Calculate the drying start and end times of each vehicle in turn. It is found through inspection that the drying end time of the 15th vehicle is 09:00 on March 16, 2025, which is later than the end point of the delivery window (08:00 on March 16, 2025), then a scheduling adjustment warning is triggered. At this time, it is necessary to re-plan the production schedule through the corresponding strategy to ensure that the drying process is completed within the delivery window while taking into account cost and quality. Among them, the corresponding strategy can be to dynamically adjust the order of vehicles entering the drying oven. The applicable scenario is that the spraying progress of some vehicles in the batch is advanced or delayed, resulting in the need to re-order the drying queue. According to the real-time data of the spraying completion time, the vehicles that have completed spraying in advance are given priority to enter the drying oven. If the drying oven supports multi-station parallel processing, the batch is split into multiple sub-queues for synchronous drying. Example: 6 vehicles are split into 2 groups (3 vehicles / group) and processed simultaneously at both ends of the drying oven, and the total duration is shortened by 50%.

[0113] In this embodiment, after the drying operation plan is formulated, the drying time of each vehicle can be monitored in real time to ensure that the delivery time is not affected. Timely discover possible problems in the production schedule, remind the staff to make adjustments, and ensure the vehicles are delivered on time.

[0114] In a preferred embodiment, the following steps are further included:

[0115] During a preset monitoring period before the drying oven runs to the first shutdown time, obtain the actual drying progress of each vehicle in this processing batch and the current residual heat temperature decay curve of the drying oven in real time;

[0116] Based on the actual drying progress, calculate the minimum required drying duration of the remaining vehicles;

[0117] If the minimum required drying duration is less than the difference between the first shutdown time and the current time, then according to the minimum required drying duration of the remaining vehicles and the current residual heat temperature decay curve of the drying oven, calculate the earliest shutdown time that can be advanced;

[0118] Update the first shutdown time with the earliest shutdown time that can be advanced, and control the drying oven to shut down at the updated time;

[0119] Among them, the earliest shutdown time that can be advanced needs to satisfy both:

[0120] The drying completion times of all remaining vehicles are not later than the end point of the delivery window;

[0121] The residual heat temperature decay curve of the drying chamber after shutdown is not lower than the minimum required temperature curve of the corresponding stage of the remaining vehicles.

[0122] Exemplarily, the preset monitoring period is 2 hours before the drying chamber runs to the first shutdown time (07:00 on March 16, 2025), that is, from 05:00 on March 16, 2025 to 07:00 on March 16, 2025. During this period, the actual drying progress of each vehicle and the current residual heat temperature decay curve of the drying chamber are obtained in real time. According to the actual drying progress, it is estimated that the shortest time required for the remaining 5 vehicles to complete the drying operation is 1 hour. The difference between the first shutdown time (07:00 on March 16, 2025) and the current time (assumed to be 05:30 on March 16, 2025) is 1.5 hours. Since the minimum required drying duration (1 hour) is less than this difference, the next step is carried out. According to the minimum required drying duration of the remaining vehicles and the current residual heat temperature decay curve of the drying chamber, it is calculated that the earliest shutdown time can be 06:00 on March 16, 2025, and it is ensured that the drying completion time of all remaining vehicles is not later than the end of the delivery window, and the residual heat temperature decay curve of the drying chamber after shutdown is not lower than the minimum required temperature curve of the corresponding stage of the remaining vehicles. Update the first shutdown time with the earliest shutdown time of 06:00 on March 16, 2025, and control the drying chamber to shut down at 06:00 on March 16, 2025. If the current drying progress and situation do not meet the early shutdown conditions, but running according to the original plan can ensure that all vehicles are dried on time and meet the quality requirements, then the original plan can be maintained and the drying chamber can be shut down normally at the first shutdown time. Or, on the premise of not affecting the drying quality and delivery time, the drying parameters of the drying chamber can be tried to be adjusted, such as increasing the temperature, increasing the wind speed, etc., to speed up the drying speed of the remaining vehicles, so that it may meet the early shutdown conditions at a subsequent moment.

[0123] In this embodiment, during the operation of the drying chamber, the drying progress and the residual heat temperature are monitored in real time, and the shutdown is advanced according to the actual situation, further reducing the electricity cost. On the premise of ensuring the drying quality and delivery time, unnecessary energy consumption is reduced by advancing the shutdown, and the electricity cost is reduced.

[0124] Embodiment 2

[0125] Based on Embodiment 1, this embodiment proposes a precise on-off control system for a drying device, which is used to implement the precise on-off control method of the drying device as described above, and includes:

[0126] A prediction module, the prediction module is configured to obtain the predicted spraying end time of the target vehicle; the target vehicle is the first vehicle in this processing batch to complete the spraying process, and the spraying process is the previous production process of the drying process;

[0127] The prediction module is further configured to determine a delivery window; wherein, the end point of the delivery window is the delivery time minus the necessary processing duration of the subsequent process of the drying process, and the start point of the delivery window is the predicted spraying end time; the delivery time is the time when the vehicle of the current processing batch is delivered to the customer.

[0128] A collection module, the collection module is configured to obtain the off-peak electricity price period and determine whether there is an overlapping period between the off-peak electricity price period and the delivery window.

[0129] The prediction module is further configured to, if so, predict the total drying duration of the drying process of the current processing batch.

[0130] A control module, the control module is configured to, if the overlapping period is equal to the total drying duration, use the start point of the overlapping period as the first drying room start time to control the start of the drying room at the first drying room start time.

[0131] In this article, specific examples are used to elaborate on the principles and implementation manners of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. The above is only the preferred implementation manner of the present application. It should be noted that due to the limitation of literal expression and objectively existing infinite specific structures, for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements, refinements or changes can be made, or the above technical features can be combined in an appropriate manner; these improvements, refinements, changes or combinations, or directly applying the concept and technical solution of the invention to other occasions without improvement, should all be regarded as the protection scope of the present application.

Claims

1. A method for accurately controlling the on / off of a drying device, characterized in that: The following steps are involved: Obtaining a predicted spraying end time of a target vehicle; the target vehicle is the first vehicle in the processing batch to complete the spraying process, and the spraying process is the production process before the drying process; Determine the delivery window; wherein the end point of the delivery window is the delivery time minus the necessary processing time of the subsequent process of the drying process, and the start point of the delivery window is the predicted spraying end time; the delivery time is the time when the vehicle of this processing batch is delivered to the customer; Obtaining an electricity price valley period, and determining whether the electricity price valley period and the delivery window have an overlapping period; If yes, predict the total drying time of the drying process for this processing batch; If the overlapping period is equal to the total drying time, the starting point of the overlapping period is used as the first drying room opening time, and the drying room is turned on at the first drying room opening time; After predicting the total drying time of the drying process of the processing batch, the following steps are also included: If the overlapping period is less than the total drying time, the remaining required drying time is calculated, and the remaining required drying time is the total drying time minus the overlapping period; Obtaining a waste heat temperature decay curve of the drying room, wherein the waste heat temperature decay curve is a curve representing a temperature drop over time after the drying room is shut down; Obtaining a minimum required temperature curve for the remaining drying stages, wherein the minimum required temperature curve is generated according to the paint film curing process requirements and is used to define the minimum temperature limits for different drying stages; Based on the waste heat temperature decay curve and the minimum required temperature curve, calculate the effective temperature maintenance time of the drying room after shutdown, the effective temperature maintenance time being the maximum continuous time that the waste heat temperature is not lower than the minimum required temperature curve; If the following conditions are met at the same time: If the remaining drying required time is less than or equal to the effective temperature maintenance time, and the sum of the starting point of the electricity price valley period, the overlapping period and the remaining drying required time is not later than the end of the delivery window, the starting point of the electricity price valley period is used as the fifth drying room opening time to control the drying room to start up.

2. The drying equipment precise on / off control method according to claim 1, characterized in that: The method of predicting the total drying time of the drying process of the processing batch further includes the following steps: Obtain target paint film parameters of the target vehicle, and the ambient temperature and humidity of the drying room at the predicted spraying end time; the target paint film parameters include paint film thickness and paint curing threshold; Calculating the preheating phase duration of the paint film of a single vehicle based on the paint film thickness and the ambient temperature; Calculate the duration of the constant temperature curing stage of the paint film of a single vehicle according to the paint curing threshold and the ambient humidity; The preheating stage duration and the constant temperature curing stage duration are weighted and summed to obtain a benchmark drying time for a single vehicle; wherein the preheating weight coefficient of the preheating stage duration and the constant temperature weight coefficient of the constant temperature curing stage duration are generated by reverse fitting of historical drying quality data; Obtain the total number of vehicles in this processing batch and the time interval between adjacent vehicles entering the drying room; The reference drying time is multiplied by the total number of vehicles, and the accumulated value of the time interval is added to obtain the total drying time.

3. The drying equipment precise on / off control method according to claim 1, characterized in that: After predicting the total drying time of the drying process of the processing batch, the following steps are also included: If the overlapping period is greater than the total drying time, selecting at least one candidate sub-period that satisfies the total drying time constraint from the overlapping period; The starting point of the candidate sub-period is used as the second drying room opening time, and the drying room is started up by controlling the second drying room opening time.

4. The drying equipment precise on / off control method according to claim 3 is characterized in that: After selecting at least one candidate sub-period satisfying the total drying time constraint from the overlapping time periods, the following steps are also included: Selecting the candidate sub-period with the longest interval from the end point of the delivery window as the first candidate sub-period; The starting point of the first candidate sub-period is used as the third drying room opening time, and the drying room is started up by controlling the third drying room opening time.

5. The drying equipment precise on / off control method according to claim 3, characterized in that: After selecting at least one candidate sub-period satisfying the total drying time constraint from the overlapping time periods, the following steps are also included: Obtain the residual heat maintenance time of the drying room and the necessary temperature control time required for subsequent processes; the residual heat maintenance time is the duration during which the temperature of the drying room is not lower than the minimum required temperature of the subsequent processes after the drying room is shut down; If the residual heat maintenance time is greater than or equal to the necessary temperature control time required for the subsequent process, the candidate sub-period whose end point is closest to the end point of the electricity price valley section is selected as the second candidate sub-period; The starting point of the second candidate sub-period is used as the fourth drying room opening time, and the drying room is started up by controlling the fourth drying room opening time.

6. The drying equipment precise on / off control method according to claim 1, characterized in that: After the fifth drying room is started by taking the starting point of the electricity price valley as the start time of the fifth drying room and controlling the drying room to start, the following steps are also included: Obtaining the end time of the total drying time, the end time being the sum of the opening time of the fifth drying chamber and the total drying time; The later of the end point of the electricity price valley section and the end point of the total drying time is used as the first shutdown time to control the shutdown of the drying room.

7. The drying equipment precise on / off control method according to claim 1, characterized in that: The following steps are also included: Obtain the predicted spraying end time and queue sequence for entering the drying room for each vehicle in this processing batch; Based on the queuing sequence, calculating the drying start time and drying end time of each vehicle; If the drying end time of any vehicle is later than the end of the delivery window, a schedule adjustment alarm is triggered.

8. The drying equipment precise on / off control method according to claim 6, characterized in that: The following steps are also included: During the preset monitoring period before the drying room runs to the first shutdown time, the actual drying progress of each vehicle in the processing batch and the current waste heat temperature decay curve of the drying room are obtained in real time; Based on the actual drying progress, calculating the minimum required drying time for the remaining vehicles; If the minimum required drying time is less than the difference between the first shutdown time and the current time, the shutdown time that can be advanced is calculated according to the minimum required drying time of the remaining vehicles and the current residual heat temperature decay curve of the drying room; Updating the first shutdown time with the advanceable shutdown time, and controlling the drying room to shut down at the updated time; The early shutdown time must meet the following conditions: The drying completion time of all remaining vehicles shall be no later than the end of the delivery window; The residual heat temperature decay curve of the drying room after shutdown is not lower than the minimum required temperature curve of the corresponding stage of the remaining vehicles.

9. A drying equipment precise on / off control system, used to implement the drying equipment precise on / off control method according to any one of claims 1 to 8, characterized in that: include: A prediction module, the prediction module is configured to obtain a predicted spraying end time of a target vehicle; the target vehicle is the first vehicle in the processing batch to complete the spraying process, and the spraying process is a production process before the drying process; The prediction module is also configured to determine a delivery window; wherein the end point of the delivery window is the delivery time minus the necessary processing time of the subsequent process of the drying process, and the start point of the delivery window is the predicted spraying end time; the delivery time is the time when the vehicle of this processing batch is delivered to the customer; A collection module, the collection module is configured to obtain the electricity price valley and determine whether the electricity price valley has an overlapping period with the delivery window; The prediction module is further configured to predict the total drying time of the drying process of the processing batch if yes; The control module is configured to use the starting point of the overlapping period as the first drying room opening time if the overlapping period is equal to the total drying time, and control the drying room to start up with the first drying room opening time.

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