Mobile phone metal frame multi-station CNC machining energy consumption optimization scheduling method

Abstract

The application discloses a kind of mobile phone metal outer frame multi-station CNC processing energy consumption optimization scheduling method, specifically related to numerical control machining scheduling optimization technical field;By constructing the energy consumption relationship data table between parts and station, the energy consumption fluctuation interval of each station is counted, and the schedulable task combination is selected in combination with power supply capacity;Collect the real-time running state of each CNC station, establish the dispatchable time period, construct the task scheduling model with the minimum energy consumption fluctuation as the target, and set the process sequence, power supply power, tool cooling and other constraint conditions;According to the model, the task sequence is solved and the scheduling plan is generated, the processing task is executed while the actual energy consumption data is collected, compared with the standard value to judge whether optimization is successful, and the energy efficiency ratio of unit product is output as the periodic energy consumption evaluation index;The application realizes the dynamic energy consumption optimization of CNC processing task, improves the energy efficiency and energy utilization rate of equipment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of numerical control machining scheduling optimization, in particular to a multi-station CNC machining energy consumption optimization scheduling method for mobile phone metal frames. BACKGROUND

[0002] With the design of intelligent mobile phone structures becoming increasingly precise and complex, the metal frame, as the core support structure of the whole machine, not only requires high-precision machining, but also needs to consider strength, heat dissipation performance and assembly consistency, resulting in long CNC multi-station machining path, large cutting amount and high process concentration. In actual production, mobile phone metal frames usually need to go through multiple CNC fine milling, drilling, chamfering and other processes, and there are different machining tool paths and power peaks between stations, forming multi-dimensional energy consumption fluctuation intervals.

[0003] Most current CNC machining energy consumption management methods only rely on a single station energy consumption total value as a reference, lacking analysis of the mutual coupling relationship between "energy consumption-task-time window" among multiple machining stations, especially under the conditions of batch machining different models or mixed line production of multiple frame sizes. It is impossible to balance the power peak through dynamic modeling, avoid simultaneous high-load start of equipment leading to local power grid voltage abnormality or overload, seriously affecting the overall equipment stability and power grid operation safety, and increasing invalid standby energy consumption and cooling system energy consumption, forming a "high energy consumption, low efficiency" situation. In addition, there are differences in execution time accuracy and nonlinear problems of load fluctuation among different CNC stations, and traditional round-robin scheduling strategy cannot dynamically adjust priority according to real-time task execution state, resulting in uneven waiting time for parts in the same batch at each station, affecting the whole line beat control and machining energy saving efficiency. SUMMARY

[0004] The purpose of the present application is to provide a multi-station CNC machining energy consumption optimization scheduling method for mobile phone metal frames to solve the problems in the background art.

[0005] In order to achieve the above purpose, the present application provides the following technical scheme: a multi-station CNC machining energy consumption optimization scheduling method for mobile phone metal frames, comprising:

[0006] Obtaining the standard machining path of each CNC station for the plurality of metal frame parts to be machined and the tool energy consumption data corresponding to each process, establishing an energy consumption relationship data table between the parts and the stations;

[0007] According to the energy consumption relationship data table, the energy consumption fluctuation interval of each CNC station under the current machining task set is calculated, and combined with the maximum allowable power value of the current power supply system, the machining task combination that can be scheduled within the energy consumption range is selected;

[0008] Collecting real-time running states of each CNC station, including remaining machining time and idle window of current task, and establishing a scheduling available time period for each station;

[0009] Building a machining task scheduling model, taking the minimum total energy fluctuation value of each station as the target, and setting constraint conditions;

[0010] Based on the machining task scheduling model, the optimal machining task sequence of each CNC station in the current cycle is solved, and the corresponding task scheduling plan is generated;

[0011] Executing the task scheduling plan, completing the machining task according to the optimized sequence, and collecting the actual energy consumption change of each station in real time during the machining process;

[0012] Judging whether the actual energy fluctuation exceeds the preset range, if it exceeds, updating the energy consumption data of each station, re-establishing the scheduling model and executing the optimization scheduling again; otherwise, continue to execute the current task plan;

[0013] According to the number of products completed in the machining cycle and the corresponding total energy consumption, the energy efficiency ratio of unit product is calculated, and the energy consumption optimization result is output.

[0014] Preferably, the energy consumption relationship data table between the parts and the stations includes:

[0015] Each metal frame part to be machined is numbered, and the standard process sequence defined in its machining process card is extracted to obtain the CNC station number corresponding to the process;

[0016] A trial run with empty stroke is carried out under the idle state of each station, and the baseline energy consumption under the condition of no machining load is recorded as the reference benchmark for tool start-stop energy consumption;

[0017] Based on the cutting behavior of the tool to different contour areas in the actual production process, unit energy consumption data under different feed rates and cutting depths are collected, and normalized calculation is carried out combined with the path length in the process card to obtain the standard tool energy consumption value of each process in the corresponding station;

[0018] The station number, machining sequence, corresponding station and standard tool energy consumption value are associated to generate the energy consumption relationship data table between the parts and the stations.

[0019] Preferably, the maximum allowable power value of the current power supply system is combined to screen out the machining task combination that can be scheduled within the energy consumption range, including:

[0020] According to the established energy consumption relationship data table between the parts and the stations, the machining processes corresponding to all tasks in the current machining batch are extracted, and classified according to the station number;

[0021] Read the weighted total energy consumption value of each task one by one, simulate the arrangement according to the task execution order, and extract the difference between the maximum energy consumption value and the minimum energy consumption value;

[0022] Obtain the maximum allowed power value of the power supply device in the current period as the upper limit power reference when each workstation is combined and operated;

[0023] Horizontally superimpose and combine the energy consumption fluctuation intervals of each workstation in the proposed operating state, retain the task arrangement order of the total load within the acceptance interval, and form the schedulable machining task combination in the current time window.

[0024] Preferably, the establishment of the schedulable time period of each workstation comprises:

[0025] Read the machining task information currently being executed on the control panel of each CNC device, and calculate the remaining machining time of the current task in combination with the actual machining start time;

[0026] Determine whether the current device is in a suspended, material waiting, emergency stopped or maintenance state, if it is in any non-machining state, the remaining machining time is considered as zero, and the current time is immediately recorded as the available start time point;

[0027] In combination with the device shift plan and the content of the shift schedule, consult the future shift device operation arrangement, and mark it as an unschedulable interval;

[0028] Take the current time as the starting point, recursively in minutes, eliminate the remaining machining time and the unschedulable interval, and form a continuous or intermittent idle time period set on each CNC device to constitute the schedulable time period of the workstation.

[0029] Preferably, the construction of the machining task scheduling model takes the minimum total energy consumption fluctuation value of each workstation as the target, and sets the constraint conditions, including:

[0030] Correspond the schedulable time period of each CNC workstation in the current time window to the set of machining tasks, initially match the executable start time of each machining task on each workstation, and extract the total machining energy consumption of the arranged tasks and the energy consumption difference between adjacent tasks according to the matched task distribution;

[0031] Optimize and adjust the task arrangement order of each workstation, and exchange the task arrangement order or insert low-energy consumption tasks to make the total energy consumption fluctuation value of the workstation tend to be the minimum;

[0032] The constraint conditions in the scheduling process are set, including: the sum of the total task machining power of each CNC station in any scheduling period does not exceed the maximum power supply allowed value of the current time period; any machining task must be completed according to the station sequence specified by its original process path, and station skipping or out-of-order processing cannot occur;

[0033] Further, the machining interval time conditions between tasks are set to ensure that the machining interval time between adjacent two tasks is not less than a preset tool cooling time threshold, and the stations with long idle intervals are preferentially allocated to high energy consumption tasks.

[0034] Preferably, the optimal machining task sequence of each CNC station in the current period is solved, including:

[0035] The schedulable task set of each CNC station is sorted, and the minimum energy consumption difference between tasks is used as the sorting principle to preferentially arrange tasks with close energy consumption, thereby forming a preliminary low fluctuation scheduling list;

[0036] In combination with the idle time period of each station, it is judged whether a task can be completely embedded or not. If a task cannot be inserted due to insufficient time period, it is moved to the next period scheduling list;

[0037] The optimal machining task sequence list of each station in the current period is formed by finally confirming the task sequence that completes the preliminary scheduling and has no conflict in time period matching.

[0038] Preferably, the machining task is completed according to the optimized sequence, and the actual energy consumption change of each station is collected in real time during the machining process, including:

[0039] The generated task scheduling plan is sent to the corresponding CNC station control interface to start the task machining process;

[0040] During the formal execution of the machining task, the real-time running current, voltage and spindle load parameters of each CNC device are continuously collected, the collected data are converted into real-time energy consumption values through a power calculation formula, and the current energy consumption level is recorded at a fixed time interval;

[0041] When each task is executed, the total energy consumption value corresponding to the task is calculated, and is compared with the standard energy consumption value in the original scheduling plan. If the difference exceeds a set error threshold, it is recorded as an energy consumption abnormal item.

[0042] Preferably, the energy efficiency ratio of unit product is calculated, and the energy consumption optimization result is output, including:

[0043] After each machining period ends, the number of machining tasks completed by all CNC stations is counted, and only the task items forming qualified parts are retained as effective output quantities;

[0044] At the same time, the actual energy consumption data of all CNC stations in the processing cycle is extracted and summed up, including spindle running power consumption, auxiliary action power consumption and cooling system energy consumption, and these data are summarized as total energy consumption value;

[0045] The total energy consumption value in the cycle is divided by the effective output quantity to calculate the energy efficiency ratio of unit product, which is used as the energy efficiency evaluation index of the cycle;

[0046] The unit product energy efficiency ratio of the current cycle is compared with the historical average value, the reference value of the same machine type or the target energy saving value. If the energy efficiency ratio decreases, it is marked as an optimization success cycle. If the energy efficiency ratio increases, the deviation amplitude is recorded and it is prompted to check the scheduling strategy, tool state or processing parameters.

[0047] In the above technical solution, the technical effects and advantages provided by the present application are as follows:

[0048] 1、The present application realizes fine management and intelligent distribution of CNC multi-station machining tasks in the energy consumption level by introducing a scheduling mechanism based on real-time energy consumption collection and station dynamic state judgment. By constructing a scheduling model with "minimum energy fluctuation" as the core target, and combining multiple constraint conditions such as actual power upper limit, tool cooling demand, process path sequence, etc., the instantaneous load impact generated when multiple devices run simultaneously is significantly reduced, effectively avoiding the problems of waste of electric power resources and fluctuation of device energy efficiency.

[0049] 2、The present application adopts a closed-loop feedback strategy, dynamically adjusts the scheduling model according to the difference between the actual machining energy consumption and the planned energy consumption of the task, so that the system has self-correction and self-optimization capabilities, improving the accuracy of scheduling response and the real-time performance of energy efficiency control. Through the unit product energy efficiency ratio evaluation mechanism, the quantitative comparison of machining efficiency and energy consumption is realized, which provides technical support and decision basis for manufacturing enterprises to improve production efficiency, and realizes energy consumption visualization, controllability and energy saving management. BRIEF DESCRIPTION OF DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can also be obtained by those skilled in the art based on these drawings.

[0051] Figure 1 The method flowchart of the present application. DETAILED DESCRIPTION

[0052] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0053] Embodiments, please refer to Figure 1 The energy consumption optimization scheduling method for the multi-station CNC machining of a mobile phone metal outer frame comprises the following steps:

[0054] A standard machining path of each metal outer frame part to be machined at each CNC station and tool energy consumption data corresponding to each machining process are acquired, and an energy consumption relationship data table between the parts and the stations is established;

[0055] According to the energy consumption relationship data table, the energy consumption fluctuation interval of each CNC station under the current machining task set is counted, and in combination with the maximum allowable power value of the current power supply system, a machining task combination that can be scheduled within the energy consumption range is screened out;

[0056] The real-time running state of each CNC station is collected, including the remaining machining time and idle window of the current task, and a scheduling available time period of each station is established;

[0057] A machining task scheduling model is constructed, taking the minimum total energy consumption fluctuation value of each station as the target and setting the constraint condition;

[0058] Based on the machining task scheduling model, the optimal machining task sequence of each CNC station within the current period is solved, and a corresponding task scheduling plan is generated;

[0059] The task scheduling plan is executed, and the machining task is completed in the optimized sequence, and the actual energy consumption change of each station is collected in real time during the machining process;

[0060] It is judged whether the actual energy consumption fluctuation exceeds the preset range, if it exceeds, the energy consumption data of each station is updated, the scheduling model is reconstructed and the optimization scheduling is executed again, otherwise, the current task plan is continued to be executed;

[0061] According to the number of products completed within the machining period and the corresponding total energy consumption, the energy efficiency ratio of unit product is calculated, and the energy consumption optimization result is output.

[0062] The core of the present application is to construct a complete "part-station-process-energy consumption" correlation data table before scheduling, which serves as the basic data support for subsequent dynamic task allocation and energy consumption optimization.

[0063] Before the processing task is assigned, first, each metal frame part to be processed is numbered. The number is generated in the combination of the preset processing batch number and the unique serial number of the part in the production plan management system, and the format is "BX20250827-001" to "BX20250827-100", and 100 pieces of metal frames to be processed are numbered in turn.

[0064] After numbering, the processing process card of the part is called manually or automatically. The process card is preset by the process engineer and confirmed by the process review process, and the content includes all processing steps from the blank feeding to the last inspection before the last inspection, including: rough milling frame shape, fine milling edge contour, drilling process, chamfering, buckle position processing, SIM card slot area fine milling, volume key hole fine hole, marking positioning, etc. Each process is clearly specified which CNC equipment to use, for example, rough milling is performed on CNC-01, drilling is performed on CNC-03, and marking is performed on CNC-08. The process card also lists in detail the tool number required for each process, the processing path length, the estimated processing time, the fixture number and the clamping method.

[0065] The engineering and technical personnel extract the processing sequence relationship of each part at all stations according to the process sequence in the process card, and pair the part number, process sequence number and station number, and record it as initial path mapping data.

[0066] Before actual table building, the energy consumption data of each station in the unloaded state needs to be obtained, so as to be used later to exclude the influence of non-cutting energy consumption. The unloaded energy consumption collection process is as follows:

[0067] Stop the normal processing task of all parts at present, empty the workbench of the CNC equipment, and do not clamp any workpiece;

[0068] Call the standard G code processing program consistent with the process of the station in the numerical control system, and set the device running path to be consistent with the actual processing path;

[0069] Start the cooling liquid supply system and keep it in working condition to ensure that the device running environment is consistent with the real cutting;

[0070] Start the spindle, tool and feed shaft, move at normal cutting speed and feed rate, record the running time in seconds;

[0071] Use an external current collection instrument (such as a multi-channel current clamp) to clamp and sample the main power line of the device, and record the voltage at the same time;

[0072] Integrate the recorded current and voltage data in the whole process of trial operation, and obtain the total energy consumption under the empty running path by multiplying the power by the time, in units of kilowatt-hours.

[0073] The no-load baseline energy consumption value is the actual energy consumption of the device when cutting without load, which is used to eliminate additional energy consumption caused by factors such as spindle start-stop, tool pre-rotation, cooling pump start-up, etc. This collection process is updated once a month, or immediately after replacing the tool, changing the process, or maintaining the device, to maintain data timeliness and accuracy.

[0074] As the core data in the entire energy consumption scheduling, the collection and processing of cutting energy consumption need to combine device sensing, process parameters, and path information. The specific process is as follows:

[0075] In the actual machining process, at least 5 different types of metal frame parts are selected and clamped on the CNC device in the normal batch order;

[0076] Before running the G code program of each machining process, manually set the collection point interval, for example, set an energy consumption collection point every 10 mm of machining path;

[0077] During the cutting process, read the real-time current value (unit: ampere), real-time voltage value (unit: volt), and spindle load percentage in the CNC spindle driver;

[0078] The machining time of each path interval is determined by the G code execution time, and the energy consumption value of the path is calculated by combining the above electrical data, with the unit of kilowatt-hour;

[0079] Divide the energy consumption value of this section by the path length of this section to get the cutting energy consumption density per unit path length, for example, 0.002 kilowatt-hour per millimeter;

[0080] For each process, the total machining path length and the weighted average of the energy consumption density of each section are used to obtain the standard tool cutting energy consumption value of the process;

[0081] If the machining materials are different, for example, 6061 and 7075 aluminum alloy, then through the comparison of historical energy consumption values of the same process and path on different materials, the material correction coefficient is set. Assuming that the energy consumption of 7075 material is 20% higher than that of the same path, the material correction coefficient is 1.20, and the final energy consumption is the standard value multiplied by 1.20.

[0082] For example, for a drilling path with a total length of 300 mm, the unit energy consumption density is 0.0018 to 0.0025 kilowatt-hour per millimeter at different feed speeds, with an average of 0.0021 kilowatt-hour per millimeter, and the total tool cutting energy consumption is 0.63 kilowatt-hour. After adding the material correction coefficient of 1.15, the final energy consumption value is 0.7245 kilowatt-hour.

[0083] After the above data is obtained, the data table is established according to the following field order:

[0084] Part number (e.g., BX20250827-001);

[0085] Process number (e.g., step 3: drilling holes for volume buttons);

[0086] CNC workstation number (e.g., CNC-03);

[0087] Processing path length (in millimeters, e.g., 270 millimeters);

[0088] Unloaded baseline energy consumption (unit: kilowatt-hour, e.g., 0.15 kilowatt-hours);

[0089] Standard cutting tool energy consumption value (unit: kilowatt-hours, e.g., 0.62 kilowatt-hours);

[0090] Material correction factor (e.g., 1.10);

[0091] Weighted total machining energy consumption (calculated as cutting energy consumption multiplied by a correction factor plus no-load energy consumption, for example 0.62×1.10+ 0.15 = 0.832 kWh).

[0092] Finally, the above records are imported into the scheduling data table, with each process for each part forming one record. For 100 parts, with an average of 8 processes per part, this results in 800 independent data items.

[0093] This energy consumption data table provides a basic input for subsequent CNC machining task scheduling. During the task allocation and energy consumption balancing process, the energy consumption data of any part at any workstation in this table can be directly called to perform refined energy consumption fluctuation analysis and time window allocation.

[0094] In this invention, in order to optimize the energy consumption of task scheduling during CNC multi-station machining, it is necessary to pre-evaluate the actual power fluctuation of each station under the current processing task conditions before the task is issued, and select task combinations that will not cause overload or excessive power fluctuations based on the actual power supply capacity of the workshop.

[0095] First, the current batch of processing tasks is broken down. Based on the previously established "Part-Station-Energy Consumption Relationship Data Table," the system or operators extract all the processing steps required for each part. These steps include, but are not limited to: rough milling, finish milling, drilling, chamfering, hole drilling, and finishing. Each step is clearly marked in the data table with its corresponding CNC station number and standard energy consumption data.

[0096] After extraction, the data is categorized and organized according to workstation number, that is, all processes to be processed are grouped according to their respective CNC workstations. For example:

[0097] CNC-01: Rough milling of the outer frame, a total of 16 tasks;

[0098] CNC-02: Drilling and chamfering, a total of 20 tasks;

[0099] CNC-03: Fine milling of the card slot, a total of 12 tasks;

[0100] CNC-04: Finishing of the structure hole, a total of 18 tasks.

[0101] This classification result will be used for subsequent energy consumption fluctuation evaluation, and avoid task overlap between stations, power statistics errors and other problems at the beginning of scheduling.

[0102] After completing the station classification, the weighted total energy consumption value of all tasks contained in each station is read in turn. This value has been uniformly calculated in the previous step by combining tool cutting energy consumption, device idle energy consumption and material correction coefficient, with the unit being kilowatt-hours.

[0103] For each CNC station, the tasks are simulated in sequence according to the processing order to form a processing sequence to be executed. Then, two extreme values are extracted in the sequence:

[0104] The maximum energy consumption value, i.e. the highest single task energy consumption value in all tasks in the processing sequence, is recorded as the maximum processing energy consumption;

[0105] The minimum energy consumption value, i.e. the lowest single task energy consumption value in the processing sequence, is recorded as the minimum processing energy consumption.

[0106] The difference between the maximum value and the minimum value is defined as the energy consumption fluctuation interval of the station under the current set of tasks to be processed. For example, for CNC-02, the maximum task energy consumption in the current 20 tasks is 1.25 kilowatt-hours, and the minimum is 0.84 kilowatt-hours, so the energy consumption fluctuation interval is 0.41 kilowatt-hours. This fluctuation interval reflects the potential power fluctuation ability of the device during task switching.

[0107] It should be particularly noted that this "energy consumption fluctuation interval" is not a real-time power curve, but a cross-task power jump range formed based on task switching, which belongs to the task combination selection basis required for early scheduling.

[0108] To ensure that all CNC devices do not exceed the current power supply capacity when running simultaneously, the maximum allowed power supply power value should be set in combination with the performance of the power supply equipment used in the production site. In this invention, a daily plan is set in time, and the power threshold is set in combination with the daytime load distribution of the workshop. For example:

[0109] Peak period (8:00 to 12:00 and 13:30 to 18:00 every day): The maximum allowed power supply power is set to 90 kilowatts;

[0110] Off-peak hours (12:00-13:30 and 18:00-21:00): the maximum allowed power is reduced to 70 kW.

[0111] The power threshold can be set by the electrical supervisor daily in the system interface or obtained once a day by the power data acquisition instrument as the power upper limit limit standard when scheduling tasks. The total energy consumption generated by the combination of all CNC stations cannot exceed this maximum value.

[0112] When the energy consumption fluctuation range of each CNC station and the current power threshold are known, the task combination screening operation is started.

[0113] The specific method is:

[0114] In the current scheduling window (such as 30 minutes or 60 minutes), combine the first several tasks (such as the first 3 tasks in each station) in the queue of each station in turn;

[0115] For each combination scheme, calculate the energy consumption value contained in the proposed running tasks of each station (including the weighted energy consumption value of the current task);

[0116] Horizontally add the energy consumption values of the proposed running tasks of each station to obtain the total processing energy consumption under this combination;

[0117] Determine whether the total energy consumption under this combination is less than or equal to the maximum allowed power value in the current time period;

[0118] If the condition is met, the task combination is retained; if the threshold is exceeded, the combination is excluded, and the next combination of tasks is selected for trial;

[0119] Among all possible combinations, combinations with total energy consumption close to the threshold but not exceeding it are preferred to maximize equipment utilization.

[0120] For example: CNC-01 selects task A (1.2 kWh), CNC-02 selects task B (0.95 kWh), CNC-03 selects task C (1.1 kWh), and CNC-04 selects task D (0.8 kWh). The sum of the four is 4.05 kWh, and if the threshold for this period is 5 kWh, then this combination is valid; if another combination is 1.5 + 1.4 + 1.3 + 1.0 = 5.2 kWh, then it is excluded.

[0121] Finally, the combination set that meets the conditions is the task combination that can be scheduled within the current power capacity, which will be used as input for subsequent scheduling plan generation, task issuance, and production scheduling execution.

[0122] In the multi-station CNC processing of mobile phone metal frame, accurate scheduling of processing tasks of each station requires real-time running status of each CNC station, including remaining processing time of current task and idle time window of equipment. Since CNC equipment is in continuous running and multi-batch interlaced processing state, its actual schedulable time period is uncertain. If the available interval of each device at different time periods cannot be accurately identified, it will directly affect the effectiveness of the scheduling plan and the balance of processing capacity.

[0123] In the production site, the running information of the current task is recorded in the control panel or upper computer software of each CNC equipment. First, the operator or the system automatically reads the following contents:

[0124] Unique number of the current processing task;

[0125] Starting time of the processing task, in time stamp or accurate to the minute;

[0126] Standard total processing time specified in the process card, in minutes;

[0127] Processing procedure content corresponding to the current task, such as rough milling, drilling, chamfering, etc.

[0128] From the above information, the running time of the current task since it started can be known, for example:

[0129] Task number A1001 started at 10:15 and the total processing time is 30 minutes;

[0130] The current time is 10:27, so the running time is 12 minutes;

[0131] The calculation method is: current time minus starting time, resulting in 12 minutes;

[0132] Remaining processing time = total time minus running time, i.e. 30 minus 12, resulting in 18 minutes.

[0133] Take 18 minutes as the remaining processing time of the current task of this station and record it in the scheduling data table to facilitate the determination of the earliest schedulable time point of the device.

[0134] For some CNC equipment, it may be in a non-processing state due to abnormal or unplanned interruptions, such as emergency stop, waiting for material, door open, alarm or maintenance. If the current task number is "none" or the device status is "pause", "standby", "under maintenance", the system considers that the device has no processing task at present.

[0135] In this state, the remaining processing time is defined as 0 minutes, and the current time is immediately set as the schedulable start time point of the station. For example:

[0136] If CNC-02 is currently in the "door open waiting for workpiece" state, the time is 10:30;

[0137] Then its remaining processing time is 0 minutes;

[0138] Available time period start = current time = 10:30.

[0139] This judgment mechanism ensures that the scheduling system responds to sudden idle states in a timely manner, avoiding the impact of original planned tasks on subsequent task insertion.

[0140] The operation of the equipment is not available all the time. In order to avoid scheduling tasks in non-processable time periods, it is necessary to identify the non-schedulable time periods of the CNC equipment within a certain period in the future.

[0141] The site usually has the following non-usable time periods:

[0142] Daily maintenance time, such as 17:30 to 18:00 every day;

[0143] Fixed tool replacement time, such as replacing the main milling cutter every 4 hours, which takes 15 minutes;

[0144] Production shift adjustment gap, such as 30 minutes of cleaning time for the handover between the middle shift and the night shift;

[0145] Weekly routine cleaning, such as centralized cleaning from 16:30 to 17:30 on Fridays.

[0146] The technician encodes the above planned non-usable time periods into the equipment operation schedule in advance, and the system reads this schedule and marks the corresponding time periods as "non-usable time intervals" within the scheduling period. These periods cannot be inserted with any new processing tasks.

[0147] On the basis of the above three steps, combined with the remaining processing time and non-usable time periods, the system begins to establish the scheduling available time period.

[0148] From the current time, calculate each minute backward;

[0149] If the current task has remaining processing time, it is considered "non-usable", and the remaining time is decreased in turn;

[0150] Until the remaining processing time is exhausted, it is considered that the equipment is idle;

[0151] If the next time period does not fall into the equipment planned maintenance, tool replacement or other non-usable interval, it is considered as continuous schedulable time;

[0152] If the timeline encounters a non-usable interval, the current available time period ends at that time, and a new interval calculation begins;

[0153] Repeat the backward scrolling until the upper limit of the scheduling period is reached (e.g. the end of the shift on the same day or 4 hours in the future).

[0154] Finally, each CNC device will get one or more schedulable time interval sets, represented by start time and end time. For example:

[0155] CNC-01 schedulable time intervals: [10:45-11:30], [12:15-13:30];

[0156] CNC-03 schedulable time intervals: [10:30-11:00], [11:15-12:00], [14:00-15:30].

[0157] This set will be used as a time limit condition for task scheduling to determine whether the task to be arranged can be inserted into these time intervals.

[0158] To further improve the practicality on site, the application also sets up a manual confirmation mechanism to allow the dispatcher to manually correct the device status.

[0159] For example: If a device is waiting for material for a long time due to sudden material shortage, the technician can mark "pause use" in the scheduling system, and the device will automatically shield the current scheduling plan; if a task is delayed, resulting in actual processing time far exceeding the estimated time, the system records the overtime information and reports it to the upper level, which is used to adjust the standard processing time estimation logic next time.

[0160] To solve the problems of large energy consumption fluctuation, frequent power impact, and tool heat accumulation caused by uneven task arrangement during the CNC multi-station processing of the metal frame of a mobile phone, the application proposes a processing task scheduling model construction method with the goal of minimizing the total value of energy consumption fluctuation, and sets up a set of executable constraint mechanism combining with the actual conditions such as workshop power supply capacity, device execution path, and tool cooling demand, to ensure the feasibility and landing of the scheduling process.

[0161] After completing the construction of the schedulable time intervals of each CNC station in the preliminary steps and preparing the task energy consumption data, the current set of tasks to be processed needs to be matched with the schedulable time intervals of each station first to determine the executable start time of each processing task on the specified station.

[0162] The matching method is as follows:

[0163] Iterate through each CNC station to find the earliest executable processing task start time within its schedulable time interval;

[0164] According to the task sequence specified in the process card, ensure that the task can only be matched at the corresponding station, and cannot be accepted by other stations;

[0165] Each successful task matching records the "expected execution period" of the task, and binds and stores it with the weighted processing energy consumption value of the task.

[0166] After completing the task and time period matching, the total energy consumption of the matched tasks at each station is counted. At the same time, according to the task execution order, the energy consumption difference value of any two adjacent tasks is extracted. For example:

[0167] If the energy consumption of two tasks arranged by station CNC-03 is 1.2 kWh and 0.8 kWh respectively;

[0168] The energy consumption difference between the two tasks is 0.4 kWh;

[0169] Take the absolute value of the energy consumption difference of each pair of adjacent tasks, and accumulate it as the total energy consumption fluctuation value of the station.

[0170] Finally, a "total energy consumption fluctuation value under the current scheduling plan" list is formed for each station, which is used for subsequent judgment and optimization.

[0171] In order to achieve the goal of minimizing the total energy consumption fluctuation value of each CNC station, the present application proposes to optimize and adjust the task sequence on the basis of preliminary arrangement. This process does not introduce algorithm solving, but uses task insertion and low energy consumption task insertion rules.

[0172] The optimization process is as follows:

[0173] Determine whether there is a situation where the energy consumption difference between consecutive tasks in the current task list of each station is greater than the preset fluctuation tolerance (such as 0.6 kWh or more);

[0174] If so, try to move the high energy consumption task forward or backward to make it adjacent to the task with closer energy consumption, avoiding the formation of "low-high-low" or "high-low-high" peak structure;

[0175] If the task movement causes execution time conflict or misses the available time period, cancel the movement attempt;

[0176] If the total number of tasks in the station is large (such as 8 or more), you can first choose to insert a medium energy consumption task between the lowest energy consumption task and the highest energy consumption task to form a buffer;

[0177] Each time an effective adjustment is completed, the energy consumption fluctuation total value of the station is recalculated, and if the fluctuation decreases, the scheme is retained.

[0178] Through the above adjustment, the task arrangement on each station is arranged to meet the time feasibility, the energy consumption difference between the continuous tasks is minimized, the energy consumption fluctuation degree of the whole processing period is reduced, and the sharp fluctuation of the instantaneous load of the workshop is avoided.

[0179] To ensure that the scheduling model can be used for actual production line execution, constraint conditions need to be introduced. The present application defines the following two core constraints:

[0180] Power constraint condition: In any scheduling period (such as every 30 minutes as a period), the sum of the energy consumption of all scheduled CNC stations in the period cannot exceed the current period power limit value.

[0181] For example: if the current power supply capability upper limit is 90 kilowatts, the CNC-01 to CNC-06 respectively plan to execute task energy consumption is 18, 16, 20, 15, 12 and 10 kilowatts;

[0182] The total energy consumption is 91 kilowatts, which exceeds the upper limit;

[0183] This combination is considered as illegal task allocation, and part of the task needs to be adjusted or delayed to the next period for execution.

[0184] Process path sequence constraint: any machining task must be completed according to the sequence of stations set in its process card, and the situation of machining path jump or task sequence reversal is not allowed.

[0185] For example: if the path of part A is “CNC-01→CNC-04→CNC-06”, the task must be executed in this order on each station;

[0186] If it is planned to be processed in CNC-04 first and then returned to CNC-01 due to time period conflict, it is considered as illegal process sequence, and the scheduling cannot be passed.

[0187] The above two constraint conditions are used as hard check standards before task arrangement, and all task scheduling plans need to meet these two conditions before entering the next stage of cooling interval matching link.

[0188] To further reduce the risk of tool overheating, reduce tool wear rate, and prolong the continuous operation life of the equipment, the present application introduces the minimum cooling interval time threshold between tasks and the task priority allocation rule.

[0189] Cooling time interval constraint: cooling time period needs to be set between any two continuous tasks, and the interval time is determined according to the power level of the machining task.

[0190] If the two continuous tasks are both high energy consumption tasks (such as energy consumption greater than 1.5 kilowatts), at least 3 minutes of idle time for natural cooling must be inserted between the tasks;

[0191] If the previous task is a high-power task and the subsequent task is a low-power task, the interval time is not less than 2 minutes.

[0192] The interval time is inserted in the form of an idle time period in the scheduling schedule and occupies the corresponding time window, participating in the scheduling judgment.

[0193] High-energy consumption task priority allocation rule: high-energy consumption tasks are preferentially arranged on workstations with long idle intervals (such as more than 30 minutes).

[0194] This rule prevents high-energy consumption tasks from being concentrated in certain short intervals, causing peak superposition.

[0195] For example, if CNC-02 has an idle interval of 40 minutes and CNC-05 has an idle interval of 20 minutes, a task with an energy consumption of 2.0 kilowatt-hours is preferentially scheduled to CNC-02.

[0196] If a high-energy consumption task is allocated to a short interval, it will result in a cooling interval that cannot be met, or the task will be delayed, reducing efficiency.

[0197] After completing the scheduling model construction and confirming that all tasks meet the basic conditions of power constraints, process sequence, and cooling interval, the schedulable task set of each CNC workstation is first sorted. The sorting principle is not based on the energy consumption of the task itself, but on the energy consumption similarity between tasks to minimize the instantaneous power fluctuation formed during the processing of adjacent tasks.

[0198] The specific sorting method is as follows:

[0199] Extract all optional tasks in the current scheduling period of each CNC workstation and record their weighted processing energy consumption values (in kilowatt-hours);

[0200] Select a task as the starting task as the first process;

[0201] Among the remaining tasks, find the task with the smallest energy consumption difference from the current task and arrange it as the next task;

[0202] Repeat the above process and arrange the tasks in sequence until the task arrangement of the workstation is complete.

[0203] For example:

[0204] If the energy consumption values of the optional tasks of CNC-01 are 1.1, 0.9, 1.2, 1.6, and 1.3 (kilowatt-hours), respectively;

[0205] The sorted result may be: 1.1→1.2→1.3→1.6→0.9;

[0206] Because the difference between 1.1 and 1.2 is 0.1, and the difference between 1.2 and 1.3 is 0.1, a continuous task sequence with the smallest energy consumption fluctuation is formed.

[0207] This sorting strategy can avoid the power load concentration problem caused by traditional high energy consumption or long task sorting.

[0208] After the initial sorting is completed, it is not directly used as the final task sequence, but further matching of the sorting results and the idle time period of each CNC station in the current cycle is required to determine whether the task can be completely embedded in the actual time window. If the task cannot be completed in full due to insufficient time period, a adjustment operation is performed.

[0209] The specific steps are as follows:

[0210] Traverse each task in the sorting list to obtain the processing time required by the task (in minutes);

[0211] Compare the processing time of the task with the current idle time period of the station;

[0212] If the time period is sufficient, the task is successfully embedded, and the start and end times are recorded in the scheduling plan;

[0213] If the time period is insufficient, for example, a task requires 25 minutes, but the available time period is only 20 minutes, the task is moved to the next cycle task pool;

[0214] To fill the gap, a task with shorter processing time (such as 15 minutes or less) and lower energy consumption can be selected from the remaining tasks to replace and insert;

[0215] After all tasks are matched, update the time utilization rate statistics of each station in the current cycle.

[0216] This step embodies the dual scheduling principle of time period matching priority and energy consumption balance supplement, which not only ensures the execution of tasks in the scheduling cycle, but also reduces the frequent start and stop of equipment caused by task truncation.

[0217] After the task order of all stations is completed and confirmed to be completely matched with the time period, the formal scheduling plan table is generated. The table takes station number as index, task order as core, and energy consumption level as reference information to form a complete task execution structure.

[0218] Each record in the plan table should include the following fields:

[0219] Station number (such as CNC-01);

[0220] Sorting number (such as 1, 2, 3, …);

[0221] Task number (such as TASK-A001);

[0222] Scheduled start time (e.g. 10:30);

[0223] Scheduled end time (e.g. 10:52);

[0224] Weighted machining energy consumption value (e.g. 1.2 kWh);

[0225] Cooling interval duration (e.g. 3 minutes, 0 if it is the first task);

[0226] Emergency task flag (e.g. yes or no, if it is high priority, the subsequent scheduling cannot be delayed);

[0227] Substitute task flag (e.g. yes or no, indicating a short period of inserted task).

[0228] For example, the scheduling table of Table 1, CNC-02, can be as follows:

[0229]

[0230] As shown in Table 1, the table will be stored in the local database or MES scheduling terminal, and pushed to the device operation panel or CNC console, and manually confirmed and prepared by the operator before the next cycle is executed.

[0231] The generated task scheduling plan is not only used for task assignment, but also serves as a basis for on-site execution tracking. The present application proposes to send the plan data to:

[0232] CNC device operation interface, displaying the next task number and machining time;

[0233] Workstation on-site display screen, scrolling the planned task sequence and cooling prompt;

[0234] Technician's handheld terminal, used to confirm the tool state and material preparation;

[0235] Production scheduling board, summarizing all workstation task progress and remaining task status.

[0236] After the scheduling plan is issued, production personnel can make device preparation, material clamping, tool preheating, etc. in advance according to the energy consumption, execution period and process requirements of each task, further reducing scheduling execution errors.

[0237] After the task scheduling table is generated, the system distributes the plan to the operation control interface of each CNC device according to the workstation number. Each plan record includes the following fields:

[0238] Task number;

[0239] Workstation number;

[0240] planned start time and end time;

[0241] designated machining path code (G code program name);

[0242] tool number;

[0243] estimated machining energy consumption value (unit: kilowatt-hour);

[0244] cooling interval recommended duration.

[0245] Before the task starts, the operator confirms the current task through the control interface, checks the tool preparation, whether the machining program matches, and whether the fixture is clamped, and confirms that there is no error, and then manually or automatically executes the start instruction, and the CNC equipment enters the task machining process. This operation ensures the consistency of the scheduling plan and the actual task execution sequence, and provides an accurate starting point for subsequent energy consumption monitoring.

[0246] During the task machining process, the present application realizes real-time energy consumption monitoring of each CNC equipment through electric parameter acquisition and power conversion. The specific acquisition content includes:

[0247] real-time current (unit: ampere);

[0248] real-time voltage (unit: volt);

[0249] spindle load (unit: percentage);

[0250] acquisition timestamp (unit: second).

[0251] The above electric parameters are extracted through external current-voltage transformers or through the state interface provided by the numerical control system of the equipment. The power conversion adopts the following method:

[0252] real-time power = real-time voltage x real-time current x power factor;

[0253] The power factor can be set according to historical statistical values, and is usually between 0.85 and 0.95.

[0254] The present application performs data acquisition and recording at fixed time intervals, and the recommended acquisition interval is once every 60 seconds, and the minimum can be set to every 30 seconds. The acquired data is stored in the "task energy consumption real-time recording table", each record is bound with the task number and the equipment number, and the power value at this time point is attached.

[0255] Through the cumulative integral method of time interval, the cumulative energy consumption value of the whole task can be obtained at the end of the task execution, that is:

[0256] actual energy consumption value (unit: kilowatt-hour) = average power of all time periods x total time interval (hours).

[0257] For example: if a task records 10 data during execution, the average power is 2.4 kW; the total time is 30 minutes, i.e. 0.5 hours; the actual energy consumption of the task is 2.4 x 0.5 = 1.2 kWh.

[0258] After each task execution is completed, the system automatically calculates the total energy consumption value of the task and compares it with the standard energy consumption value recorded in the scheduling plan. The standard energy consumption value is a theoretical reference value calculated in advance according to the task path, tool characteristics and material correction coefficient.

[0259] To determine whether there is an energy consumption anomaly, the present application sets an energy consumption difference error threshold Δ, i.e.

[0260] If | actual energy consumption value - standard energy consumption value | ÷ standard energy consumption value ≥ Δ, it is considered abnormal;

[0261] Where the recommended value of Δ is 10%, which can be adjusted to between 5% and 15% according to the stability of the production line.

[0262] For example: the standard energy consumption of a task is 1.1 kWh, the actual energy consumption is 1.28 kWh; the difference is 0.18 kWh, accounting for 16.36%; exceeding the 10% threshold, the system automatically records the task as an energy consumption anomaly item and marks it as a red prompt.

[0263] All energy consumption abnormal tasks will be recorded in the "Abnormal Energy Consumption Task Table", which includes:

[0264] Workstation number;

[0265] Task number;

[0266] Standard energy consumption value;

[0267] Actual energy consumption value;

[0268] Error percentage;

[0269] Abnormal marker state.

[0270] This table will be used for subsequent scheduling strategy adjustment, machining process correction or tool health diagnosis, etc.

[0271] After each CNC workstation completes at least one round of task execution, the system compares the actual energy consumption data of all tasks in the current scheduling period with the standard energy consumption data predicted in the scheduling model and calculates the overall fluctuation. The fluctuation amplitude is calculated as follows:

[0272] First, calculate the difference between the actual energy consumption and the standard energy consumption of each task;

[0273] Then, calculate the sum of the absolute values of the differences of all tasks;

[0274] Finally, divide the total difference by the total standard energy consumption to obtain the fluctuation percentage.

[0275] For example, if a station performs 3 tasks in the current period, the total standard energy consumption is 3.2 kWh, and the total actual energy consumption is 3.8 kWh, the difference is 0.6 kWh, and the fluctuation range is 0.6 divided by 3.2, about 18.75%.

[0276] In the present application, an energy consumption fluctuation judgment threshold ΔW is set, i.e. the allowed overall energy consumption deviation ratio. The threshold can be determined according to field experience or statistical methods, and the initial setting is recommended to be 15%. This value indicates that when the actual total energy consumption fluctuation range exceeds 15% of the standard plan, the current scheduling model is considered to be no longer suitable for the current production state.

[0277] This threshold can be adjusted according to the following factors:

[0278] When the material hardness changes frequently, increase to 20%;

[0279] When the tool stability is good, reduce to 10%;

[0280] When high precision is required, the section is fixed to 12% as a strict control value.

[0281] After completing the fluctuation range calculation, the system determines whether to rebuild the scheduling model according to the following logic:

[0282] If the fluctuation percentage is less than or equal to the preset threshold ΔW, it is considered that the existing model is still suitable for the current production state, and the remaining tasks are continued to be executed without adjustment;

[0283] If the fluctuation percentage is greater than ΔW, it is determined that the prediction accuracy of the current model has decreased, and model updating is needed, entering the process of rebuilding the scheduling model.

[0284] The model updating process includes:

[0285] Replace the standard values in the original energy consumption relationship data table with the actual energy consumption values of the latest round of tasks;

[0286] Re-statistic the energy consumption fluctuation range of each station according to the updated data;

[0287] Re-evaluate the power distribution, scheduling order, and idle time period embedding relationship;

[0288] Execute the new task sorting logic to generate an updated scheduling plan table.

[0289] The system will complete all model updating and new plan generation before the start of the next scheduling period, ensuring that the new plan is synchronized and matched with the current device state.

[0290] At the end of each scheduling cycle, the system first extracts all the processing task entries in this cycle from the CNC station task execution record, and selects the effective output quantity based on the following two judgment conditions:

[0291] The task has been completed and marked as "completed" status;

[0292] The corresponding part is determined as "qualified" in the final inspection or intermediate inspection link.

[0293] The system will simultaneously associate the process execution system with the quality management system, and eliminate the interrupted tasks, repeated processing tasks or unqualified part processing tasks caused by factors such as tool abnormality, program error, equipment failure, etc. The final statistical task quantity is the actual completed qualified part quantity in this cycle, which is recorded as the effective output quantity N, unit: pieces.

[0294] For example:

[0295] If CNC-01 to CNC-06 execute 120 processing tasks in this cycle;

[0296] Among them, the number of tasks with "normal" completion mark and qualified products passing quality inspection is 112;

[0297] The effective output quantity is 112 pieces.

[0298] At the same time of statistical output quantity, the system extracts the actual energy consumption data in this cycle from the energy consumption collection data of each CNC station, and classifies and statistics according to the energy consumption sources, including:

[0299] Spindle running power consumption: refers to the power consumption of spindle drive motor in the task processing process, the data is collected by spindle controller or power meter, unit: kilowatt hour;

[0300] Auxiliary action power consumption: including tool changing, feeding, clamping, door opening and closing, program transmission and other non-spindle but necessary action power consumption in equipment operation;

[0301] Cooling system energy consumption: including the running power consumption of auxiliary systems such as main cooling pump, atomization system, oil mist purification and tool spraying.

[0302] Each station records the above three types of energy consumption data and transmits them to the energy management database. The system sums up the energy consumption values of each station and each type in this cycle to form a unified total energy consumption value E, unit: kilowatt hour.

[0303] For example:

[0304] The total spindle power consumption is 140 kilowatt hours;

[0305] The auxiliary action power consumption is 38 kilowatt hours;

[0306] The cooling system consumes 22 kWh of energy.

[0307] The total energy consumption E of the current cycle is 200 kWh.

[0308] The energy efficiency ratio (η) per unit product is defined as the average energy consumption value corresponding to the processing of one qualified part in a complete processing cycle. The calculation formula is:

[0309] The energy efficiency ratio η per unit product is defined as the average energy consumption value corresponding to the processing of one qualified part in a complete processing cycle. The calculation formula is:

[0310] Taking the above example data as an example:

[0311] The total energy consumption E is 200 kWh.

[0312] The effective output quantity N is 112 pieces.

[0313] Therefore, the energy efficiency ratio η per unit product is 200÷112≈1.79 kWh / piece.

[0314] This index is used as a key reference value in the energy efficiency evaluation of the workshop level, and will be recorded in the "cycle energy efficiency file", and will be used as an input variable for the scheduling decision of the next cycle.

[0315] The judgment method of energy efficiency optimization set by the present application is to compare the energy efficiency ratio η per unit product of the current cycle with the reference value to determine whether the optimization target is reached. The reference value can be selected from the following sources:

[0316] Historical average value : The average energy consumption per unit of the same type of product in the same workshop with the same equipment configuration in the past several cycles;

[0317] Comparison value of the same model : The unit energy consumption benchmark when processing the same type of product on different production lines or equipment;

[0318] Target energy saving value : The energy saving evaluation target value set by the energy management or process management team.

[0319] The judgment logic is as follows:

[0320] If η ≤ (reference value), it indicates that the unit energy consumption has decreased, and the system marks the current cycle as "optimization success cycle";

[0321] If η > , the system calculates the difference as the deviation amplitude, and records the reason for the abnormal cycle.

[0322] At the same time, the system will send a prompt message to suggest that the production manager check the following elements:

[0323] Whether the dispatching sequence or load arrangement is unreasonable recently;

[0324] Whether there are factors such as tool aging, abnormal feed speed, and prolonged idle running time;

[0325] Whether there are abnormal phenomena such as CNC equipment running state fluctuation or cooling system energy efficiency decline.

[0326] All deviation periods and suggestions will be recorded in the energy efficiency deviation record table, including period number, energy efficiency ratio, deviation amplitude, and suggested inspection items, etc. fields, to facilitate subsequent process correction and dispatching strategy iteration.

[0327] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A method for optimizing energy consumption scheduling in multi-station CNC machining of mobile phone metal frames, characterized in that: include: Obtain the standard machining paths of multiple metal frame parts to be processed at each CNC station and the tool energy consumption data corresponding to each process, and establish a data table of energy consumption relationship between parts and stations; The process of establishing an energy consumption relationship data table between parts and workstations includes: numbering each metal frame part to be processed and extracting the standard process sequence defined in its processing process card to obtain the CNC workstation number corresponding to the process; performing a no-load trial run at each workstation and recording the baseline energy consumption under no-processing load conditions as a reference benchmark for tool start-stop energy consumption; collecting unit energy consumption data at different feed rates and depths of cut based on the cutting behavior of the tool on different contour areas during actual production, and performing normalization calculations in conjunction with the path length in the process card to obtain the standard tool energy consumption value for each process at the corresponding workstation; and associating the workstation number, processing sequence, corresponding workstation, and standard tool energy consumption value to generate an energy consumption relationship data table between parts and workstations. Based on the energy consumption data table, the energy consumption fluctuation range of each CNC station under the current set of tasks to be processed is statistically analyzed. Combined with the maximum allowable power value of the current power supply system, the schedulable processing task combinations within the energy consumption range are selected, including: Based on the established energy consumption relationship data table between parts and workstations, extract the processing procedures corresponding to all tasks in the current processing batch and classify them according to workstation number; For each workstation, the weighted total energy consumption value of each task is read one by one, and the tasks are arranged in the order of execution. The difference between the maximum and minimum energy consumption values ​​is then extracted. Obtain the maximum allowable power value of the power supply equipment during the current time period, and use it as a reference for the upper limit power of each workstation combination during operation; The energy consumption fluctuation ranges of each workstation under the intended operating state are horizontally superimposed and combined, and the task arrangement order within the total load is retained to form a combination of schedulable processing tasks within the current time window. Collect the real-time operating status of each CNC station, including the remaining processing time and idle window of the current task, and establish the available time period for scheduling each station; The establishment of the available scheduling time period for each workstation includes: Read the currently executing machining task information on the control panel of each CNC machine, and calculate the remaining machining time of the current task based on the actual machining start time; Determine whether the current equipment is in a paused, waiting for material, emergency stop, or maintenance state. If it is in any non-processing state, its remaining processing time is considered to be zero, and the current time is immediately recorded as the available start time point. Based on the equipment shift plan and schedule, review the equipment operation arrangements for future shifts and mark the unschedulable intervals. Starting from the current time, proceed backward in minutes, eliminating remaining processing time and unschedulable intervals, forming a set of continuous or intermittent idle time periods on each CNC machine, which constitutes the available time period for scheduling the workstation. A processing task scheduling model is constructed with the objective of minimizing the total energy consumption fluctuation of each workstation, and constraints are set, including: The available time slots for scheduling each CNC workstation within the current time window are matched with the set of tasks to be processed. The start time of each processing task at each workstation is initially matched. Based on the matched task distribution, the total processing energy consumption of the scheduled tasks at each workstation and the energy consumption difference between adjacent tasks are extracted. The task arrangement order of each workstation is optimized and adjusted by changing the task arrangement order or inserting low-energy-consumption tasks, so as to minimize the total energy consumption fluctuation of the workstation. Set constraints during the scheduling process, including: the total processing power of each CNC station in any scheduling cycle shall not exceed the maximum allowable power supply value for the current time period; any processing task must be completed in the station sequence specified by its original process path, and station jumps or out-of-order processing are not allowed. Further set the processing interval time conditions between tasks to ensure that no less than the preset tool cooling time threshold is reserved between two adjacent tasks, and at the same time prioritize the allocation of workstations with long idle intervals to high energy consumption tasks. Based on the aforementioned machining task scheduling model, the optimal machining task sequence for each CNC station in the current cycle is solved, and a corresponding task scheduling plan is generated. The task scheduling plan is executed to complete the processing tasks in an optimized order, and the actual energy consumption changes of each workstation are collected in real time during the processing. Determine whether the actual energy consumption fluctuation exceeds the preset range. If it does, update the energy consumption data of each workstation, rebuild the scheduling model, and execute the optimized scheduling again; otherwise, continue to execute the current task plan. Based on the number of products completed within the processing cycle and the corresponding total energy consumption, calculate the energy efficiency ratio per unit product and output the energy consumption optimization results.

2. The energy consumption optimization and scheduling method for multi-station CNC machining of mobile phone metal frames according to claim 1, characterized in that: The process of determining the optimal machining task sequence for each CNC station within the current cycle includes: The set of schedulable tasks for each CNC workstation is sorted, and tasks with similar energy consumption are prioritized based on the principle of minimizing the energy consumption difference between tasks, thus forming a preliminary low-fluctuation scheduling list. Based on the available time slots of each workstation, determine whether each task can be fully embedded. If a task cannot be inserted due to insufficient time slots, move it to the scheduling list of the next cycle. The order of tasks that have completed the initial scheduling and whose time periods match without conflict is finally confirmed to form the optimal processing task order list for each workstation in the current cycle.

3. The energy consumption optimization and scheduling method for multi-station CNC machining of mobile phone metal frames according to claim 2, characterized in that: The process of completing the processing tasks in an optimized order and collecting real-time data on the actual energy consumption changes at each workstation during processing includes: Send the generated task scheduling plans to the corresponding CNC workstation control interfaces to start the task processing flow; During the formal execution of the machining task, the real-time operating current, voltage and spindle load parameters of each CNC equipment are continuously collected. The collected data are converted into real-time energy consumption values ​​through the power calculation formula, and the current energy consumption level is recorded at fixed time intervals. When each task is completed, the total energy consumption value corresponding to the task is calculated and compared with the standard energy consumption value in the original scheduling plan. If the difference exceeds the set error threshold, it is recorded as an energy consumption anomaly.

4. The energy consumption optimization scheduling method for multi-station CNC machining of mobile phone metal frames according to claim 3, characterized in that: The calculation of the energy efficiency ratio per unit product and the output of energy consumption optimization results include: After each processing cycle, count the number of processing tasks completed by all CNC stations, and retain only the task entries that form qualified parts as the effective output quantity. Simultaneously, extract the total actual energy consumption data of all CNC stations within the machining cycle, including spindle power consumption, auxiliary motion power consumption, and cooling system energy consumption, and summarize these data into a total energy consumption value. The energy efficiency ratio per unit product is calculated by dividing the total energy consumption within the cycle by the effective output quantity, and this ratio serves as the energy efficiency evaluation index for the cycle. Compare the unit product energy efficiency ratio of the current cycle with the historical average, the reference value of the same model, or the target energy saving value. If the energy efficiency ratio decreases, mark it as a successful optimization cycle; if the energy efficiency ratio increases, record the deviation and prompt that the scheduling strategy, tool status, or machining process parameters need to be checked.

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