Energy feedback-based energy-saving control system for spindle driving of PCB panel dividing machine

Abstract

This invention proposes an energy-saving control system for the spindle drive of a PCB depaneling machine based on energy feedback. The system includes: a spindle running segment generation module, a feedback-capable empty cutting window determination module, a restricted weak reverse magnetization control quantity generation module, and a spindle drive energy feedback execution module. The system identifies spindle running segments with stable load boundaries by reading the toolpath file and the real-time spindle status, and accordingly selects safe and efficient feedback-capable empty cutting windows. For each window, the system dynamically generates a restricted weak reverse magnetization control quantity, sending specific excitation and torque current adjustments to the spindle driver, causing the spindle to enter a restricted power generation state during the non-cutting phase, converting rotational inertia into electrical energy fed back to the DC bus, and smoothly converging at the end of the window. This invention significantly reduces the energy consumption of the depaneling machine without increasing hardware costs, while ensuring processing accuracy and efficiency.

Description

Technical Field

[0001] This invention belongs to the field of automation technology for electronic manufacturing equipment, and particularly relates to an energy-saving control system for the spindle drive of a PCB depaneling machine based on energy feedback. Background Technology

[0002] PCB depaneling machines are typically used to separate panelized PCBs along a preset cutting path. Existing equipment generally uses a milling cutter spindle, a saw blade spindle, or a combination of milling cutter and saw blade spindles to complete the processing, and is equipped with dual platforms, online conveyors, fixture positioning, and loading / unloading mechanisms to achieve continuous operation. In actual operation, the spindle drive system often uses frequency converters or servo drives to control the spindle motor to run at a set speed. Current control focuses mainly on spindle speed stability, maintaining cutting accuracy, start / stop response, and overload protection. Some drives can feed back the energy released by the motor's inertia to the DC bus or dissipate it through a braking resistor when the spindle decelerates, stops, or stops suddenly, in order to prevent the bus voltage from rising. This type of feedback method is based on significant speed reduction or shutdown conditions and is suitable for handling the release of inertial energy when the spindle speed command changes significantly. However, the actual processing of PCB depaneling machines is significantly different: there are numerous short-distance tool jumps between panel units, there is avoidance movement after the board edge is cut, there is platform switching waiting in online or offline dual-platform equipment, and the milling cutter or saw blade will also undergo repositioning and short-term waiting before entering the next cutting path. During the above stages, the spindle usually maintains a high speed to ensure stable cutting quality when the tool re-enters the PCB, but the tool has already left the effective cutting area of ​​the PCB, and the spindle load drops significantly, forming a short-term, high-frequency, and scattered high-speed dry-cutting state. Existing spindle drive control usually treats this type of state as a normal constant-speed operation stage, and continues to use speed closed-loop compensation for mechanical loss, wind resistance loss, and minor load disturbances. The rotational inertia stored in the spindle is not actively converted into usable electrical energy during the dry-cutting stage. Meanwhile, the dry cutting phase of PCB depaneling machines is short, and there is a lag between toolpath switching and actual load stabilization. Even at the moment the tool leaves the board, current fluctuations may occur due to edge friction, broken residual connection points, or saw blade micro-vibration. If the dry cutting state is determined solely by the toolpath type, feedback control may be prematurely implemented. Conversely, if the low load state is determined solely by the spindle current, the time constraint for the next entry may be overlooked. Applying a conventional deceleration feedback approach directly to this scenario can easily cause excessive spindle speed reduction, resulting in insufficient speed recovery before the next entry, leading to cutting impact, edge burrs, chipping, saw blade whistling, or processing cycle delays. Therefore, existing technologies still present significant engineering problems in PCB depaneling machine spindle energy-saving control: the rotational inertia during the dry cutting phase is not effectively identified and utilized, and there is a lack of continuous correlation between feedback control and toolpath type, spindle load stability, and recovery margin for the next entry. This makes it difficult to maintain depaneling quality and processing cycle stability while reducing dry cutting energy consumption. Especially in online dual-platform or high-density panel processing scenarios, there are many air-cutting segments but each segment is relatively short. Only by simultaneously incorporating the toolpath file, real-time spindle drive parameters, and tool entry recovery boundary into the control can we avoid misjudging normal cutting fluctuations as feedback windows. Summary of the Invention

[0003] The purpose of this invention is to design an energy-saving control system for the spindle drive of a PCB depaneling machine based on energy feedback. This system can adaptively simulate the teaching process, guide cognitive transfer, and dynamically adjust the pace of content, truly realizing a three-in-one teaching experience of intelligence, immersion, and interaction, and significantly improving students' learning efficiency and depth of understanding.

[0004] To achieve the above objectives, the present invention provides an energy-saving control system for the spindle drive of a PCB depaneling machine based on energy feedback, the system comprising:

[0005] The spindle running segment generation module is used to read the toolpath segment type in the local toolpath file and simultaneously read the actual spindle speed and spindle current. When the changes in toolpath segment type and spindle current both meet the stability conditions, it generates a spindle running segment sequence with stable load boundaries.

[0006] The feedback empty cutting window determination module is used to receive the spindle running segment sequence and determine the feedback empty cutting window set from the spindle running segment sequence based on the toolpath segment type, spindle speed maintenance degree, load release degree and recovery margin before the next tool entry;

[0007] The restricted weak reversible magnetization control quantity generation module is used to receive the set of feedback open-cut windows, convert the permissibility of each feedback open-cut window into a restricted weak reversible magnetization coefficient, and determine the control action duration by combining the window duration and the spindle recovery time, thereby generating a restricted weak reversible magnetization control quantity sequence.

[0008] The spindle drive energy feedback execution module is used to receive the restricted weak reverse magnetization control quantity sequence, and according to the control time and control duration in the control sequence, send the excitation current adjustment quantity and torque current adjustment quantity to the spindle driver to make the spindle enter the restricted power generation state. At the end of the window, the feedback effect is gradually converged according to the spindle speed protection boundary to feed the rotational inertia back to the DC bus.

[0009] Furthermore, the spindle running segment generation module is specifically used for:

[0010] The toolpath timing, spindle speed sampling, and spindle current sampling are aligned using a unified timestamp.

[0011] Calculate the relative change value of the spindle current in adjacent sampling periods. When the tool path segment type remains unchanged and the relative change value of the spindle current is less than the preset stability threshold in several consecutive sampling periods, the current spindle load is confirmed to be stable, and the stable starting point is taken as the effective starting position of the spindle running segment.

[0012] When the toolpath segment type is switched, or when the relative change value of the spindle current continuously exceeds the preset stable threshold, the current segment ends, forming a spindle running segment sequence arranged in the order of processing time.

[0013] Furthermore, the feedback-enabled empty-cut window determination module is specifically used for:

[0014] Candidate air cut segments with toolpath types of jump movement, avoidance movement, or waiting action are selected from the spindle running segment sequence;

[0015] The air-cut feedback allowance of the candidate air-cut segment is calculated. The air-cut feedback allowance is a comprehensive judgment value based on the ratio of the average spindle speed of the segment to the reference speed, the ratio of the average spindle current of the segment to the cutting current threshold, and the time margin from the end of the segment to the start of the next cutting.

[0016] Candidate empty cut segments with an empty cut feedback permission degree greater than the permission threshold are written into the set of empty cut windows that can receive feedback.

[0017] Furthermore, the restricted weak reverse magnetization control quantity generation module is specifically used for:

[0018] The permissibility of the permissible ...

[0019] The reserved recovery time at the end of the window is adjusted according to the restricted weak dimagnetization coefficient, and the duration of weak dimagnetization control allowed to be performed within the window is calculated.

[0020] The preset reference adjustment amount is scaled proportionally according to the restricted weak reverse magnetization coefficient to generate the excitation current adjustment amount and torque current adjustment amount corresponding to each window.

[0021] Furthermore, the restricted weak reverse magnetization control quantity generation module is also specifically used for:

[0022] Verify the excitation current regulation, torque current regulation, and driver feedback capability. If the driver protection limit is exceeded, mark the window as an unexecutable window.

[0023] The restricted weak reverse magnetization control quantity sequence includes the corresponding window number, control start time, control end time, weak reverse magnetization control duration, restricted weak reverse magnetization coefficient, excitation current adjustment quantity, and torque current adjustment quantity.

[0024] Furthermore, the spindle drive energy feedback execution module is specifically used for:

[0025] When the control start time arrives, the excitation current regulation and torque current regulation in the restricted weak reverse magnetization control quantity sequence are read, and applied to the excitation current channel and torque current channel of the spindle driver according to the preset current ramp, so that the spindle enters the restricted power generation state from the speed holding state.

[0026] Furthermore, the spindle drive energy feedback execution module is also specifically used for:

[0027] The actual spindle speed is read in real time, and the current regulation convergence coefficient is calculated. The current regulation convergence coefficient is determined based on the relative relationship between the actual spindle speed and the speed protection boundary.

[0028] The excitation current regulation and torque current regulation are multiplied by the current regulation convergence coefficient and then written into the spindle driver, so that the spindle can smoothly exit the restricted power generation state when it approaches the speed protection boundary.

[0029] Furthermore, the speed protection boundary is determined jointly by the spindle reference speed set in the current machining program and the process allowable speed drop coefficient;

[0030] When the actual spindle speed is lower than the speed protection boundary, the current regulation convergence coefficient is immediately set to zero and normal speed maintenance control is restored.

[0031] Furthermore, the spindle drive energy feedback execution module is also specifically used for:

[0032] After the control duration ends or the system time reaches the control end time, the excitation current adjustment and torque current adjustment are canceled according to the current ramp, and the target speed control is maintained at the end of the window to ensure that the spindle is in a stable operating state before the next cut.

[0033] Furthermore, it also includes an energy statistics module, which is used to accumulate the product of DC bus voltage and DC bus feedback current over time during the period when the spindle is in a limited power generation state, so as to obtain the spindle air cutting recovery energy of this machining process.

[0034] The beneficial technical effects of the present invention are at least as follows:

[0035] To address the aforementioned issues, this invention provides an energy-saving control system for the spindle drive of a PCB depaneling machine based on energy feedback. By deeply exploring the unique processing characteristics of PCB depaneling machines, the system converts the rotational inertia of the spindle during the high-speed air-cutting phase into usable electrical energy, significantly reducing the overall power consumption of the equipment and achieving green production. This system establishes a mapping relationship between the spindle running segment sequence and the feedback air-cutting window, ensuring that energy feedback only occurs during the air-cutting phase with process safety boundaries. This perfectly solves the technical problems of excessive spindle speed drop and unstable cutting quality upon re-entry caused by ordinary deceleration feedback. By introducing a restricted weak reverse magnetization control strategy, the system can dynamically adjust the feedback intensity and duration based on the window length, spindle recovery time, and load status, ensuring maximum energy recovery while also considering the speed recovery margin before the next entry. This technical solution requires no additional hardware costs and can be implemented solely through control algorithm optimization, possessing high engineering application value. It is particularly suitable for high-density panelization, online dual-platform, and other high-frequency tool-jumping processing scenarios, effectively improving the energy utilization efficiency and processing cycle stability of PCB depaneling machines. Attached Figure Description

[0036] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0037] Figure 1 This is a flowchart of an energy-saving control system for the spindle drive of a PCB depaneling machine based on energy feedback, according to the present invention. Detailed Implementation

[0038] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0039] In one or more embodiments, such as Figure 1 As shown, an energy-saving control system for the spindle drive of a PCB depaneling machine based on energy feedback is disclosed. The system includes the following:

[0040] The spindle running segment generation module is used to read the toolpath segment type in the local toolpath file and simultaneously read the actual spindle speed and spindle current. When the changes in toolpath segment type and spindle current both meet the stability conditions, a spindle running segment sequence with stable load boundaries is generated.

[0041] The execution steps for this module are as follows:

[0042] Step 1 is used to generate the spindle running segment sequence. During PCB depaneling, the spindle's operating status changes frequently depending on the toolpath segment type, but the toolpath segment switching is not completely synchronized with the actual load stability. For example, after the tool leaves the PCB edge, the toolpath file has entered the skip segment, but tool edge friction, residual stress release from the board, or saw blade micro-vibration may still cause short-term fluctuations in the spindle current. The device controller reads the toolpath segment type from the local toolpath file and simultaneously reads the actual spindle speed. and spindle current The spindle operation segment is generated when both the toolpath segment type and spindle current variation meet stable conditions. The toolpath segment type is read by the equipment controller from the G-code file or the factory-defined machining path file. The segment types in the path file include cutting movement, tool skipping movement, avoidance movement, and waiting action; the actual spindle speed... Provided by the spindle encoder or driver speed measurement module, used to record the spindle operating status within a segment; spindle current. Provided by the internal current sampling module of the spindle driver, this data is used to determine whether the spindle load within the segment has transitioned from a cutting load to a stable load. This data is generated in the local control link of the equipment, enabling the spindle running segments to reflect the short-path, high-frequency switching, and significant load transients characteristic of the PCB depaneling machine. Before generating the segment, the equipment controller performs unified timestamp alignment on the toolpath time, speed sampling, and current sampling. If the toolpath segment marker is missing, the encoder speed measurement is abnormal, the current sampling is saturated, or the sampling time difference exceeds the controller's allowable error, the segment will not be included in subsequent feedback judgment and will only be saved as a normal spindle running record.

[0043] The spindle current stability is determined by the relative change relationship between adjacent sampled values. This relationship is derived from the mathematical definition of relative rate of change, which is the difference between two adjacent measurements divided by the previous measurement to characterize the magnitude of the current change relative to the previous level. This application adds a small bias amount to this definition to reduce abnormal fluctuations caused by an excessively small denominator during low-load or near-no-load spindle operation. The specific calculation is as follows:

[0044] ;

[0045] in, For the first The relative change in spindle current for each sampling period is calculated by the device controller based on the spindle current in two adjacent sampling periods. For the first The spindle current for each sampling period is read by the internal current sampling module of the spindle driver. The spindle current from the previous sampling period is buffered by the controller; This is a small bias value from the controller parameter table, used to stabilize the calculation results during low-load periods. Here, the spindle current... Use the effective value of the load current output by the driver or the current amplitude after absolute value processing to ensure that it is a non-negative value; The sampling resolution is set during the equipment commissioning phase based on the no-load current and saved in correspondence with the spindle specifications and driver model. In this formula, both the numerator and denominator represent the same type of current, and the calculated result is a relative value that can be directly compared with a preset stability threshold. Using relative change values ​​allows for adaptation to PCB depaneling machines with different spindle specifications. For example, the spindle current levels of the ZM300N single-spindle milling cutter model and the ZM360AT large-size milling cutter model differ; relative change values ​​ensure that spindles of different power specifications employ consistent stability judgment logic.

[0046] The controller reads the spindle current and calculates it according to a fixed sampling period. When the tool path segment type remains unchanged, and within several consecutive sampling periods... When all values ​​are less than the preset stability threshold, the controller confirms that the current spindle load has stabilized and uses this stable starting point as the valid starting position of the spindle running segment. When the toolpath segment type switches again, or the relative change value of the spindle current continuously exceeds the preset stability threshold, the controller ends the current segment. The fixed sampling period, the number of consecutive sampling periods, the preset stability threshold, and the minimum segment duration are all written into the controller parameter table and configured according to the spindle type, tool type, and sheet metal process. If the duration of a segment is shorter than the minimum segment duration, even if it meets the stability threshold, it will not be considered as a candidate segment for subsequent feedback of the empty cutting window to avoid false triggering caused by short transient segments. In the skip section of a saw blade type online dual-platform depaneling machine, the spindle driver continuously samples and obtains... , Controller parameter table Substituting into the above formula, we get When the stability threshold is set to If the sampling period meets the stability condition, and subsequent consecutive sampling periods are also below the threshold, the controller records this tool skip segment as a stable spindle operation segment. If the sampled value is when the tool just leaves the PCB edge... , ,but This state reflects that the spindle load is still in a phase of significant fluctuation, and the controller continues to wait for subsequent sampled values ​​to enter a stable range before determining the segment start position.

[0047] The final sequence of spindle running segments Arranged chronologically by processing time, each segment records at least the segment number, toolpath type, segment start time, segment end time, average spindle speed, and average spindle current. The segment number is automatically generated by the controller in chronological order; the toolpath type is derived from the local toolpath file; the segment start and end times are recorded by the controller clock; the average spindle speed is derived from the spindle encoder values ​​within that segment; and the average spindle current is derived from the spindle driver current samples within that segment. Each segment also saves the toolpath file identifier, spindle type, valid sampling flag, and stability determination result for subsequent verification of whether the segment meets the feedback judgment criteria. This will serve as input for the next step of determining the set of empty cut windows that can provide feedback; not yet entered. Abnormal or unstable segments will not be identified as feedback windows in step two.

[0048] The feedback empty cutting window determination module is used to receive the spindle running segment sequence and determine the feedback empty cutting window set from the spindle running segment sequence based on the toolpath segment type, spindle speed maintenance degree, load release degree, and recovery margin before the next tool entry.

[0049] The execution steps for this module are as follows:

[0050] Step two is the spindle running segment sequence output from step one. Determine the set of empty cut windows that can provide feedback . Each spindle operation segment already includes a segment number, toolpath type, segment start time, segment end time, average spindle speed, and average spindle current. This step uses these segments as the processing objects, judging whether each segment can be used as a spindle energy feedback window according to the processing time sequence. For PCB depaneling machines, a cut segment that can be used for feedback should simultaneously meet three conditions: First, the tool is already in a jump-movement, avoidance movement, or waiting action, indicating that the segment has no effective cutting; second, the spindle still maintains a high speed, indicating that the spindle still has usable rotational inertia; third, the segment still has a recovery margin before the next cut, indicating that the spindle can still recover to the target speed after performing limited feedback. The controller first determines based on... Select candidate air-cut segments from the knife path segment types, and then... The system searches backwards for the nearest cutting movement segment to the candidate segment and reads the start time of that segment to calculate the recovery allowance before the next cut. If there is no next cutting movement segment after the candidate segment and the machining program is about to end or enters a plate change waiting phase, the controller can record this segment separately as an end-of-line safety feedback segment; if the subsequent state cannot be confirmed, it will not be written into the system. This avoids the lack of a reference point for recovery after the initial incision.

[0051] This step uses the empty-cut feedback permission degree. For the The candidate cut segments are comprehensively evaluated. This calculation is based on three classic engineering judgments: the spindle speed level uses the ratio of actual speed to reference speed, derived from speed normalization judgment commonly used in rotating machinery control; the load shedding degree uses the ratio of actual load current to cutting current threshold, derived from the basic method of using current to characterize load size in motor drives; and the recovery margin uses the time margin between the end of the candidate segment and the start of the next cut, derived from the time interval judgment between adjacent events in motion control. This application couples these three judgments in a product manner, so that the permissibility of the candidate segment decreases when the spindle speed is insufficient, the cutting load is not fully shedding, or the next cut is too close, thus adapting to the short-path, high-frequency tool skipping, and tool entry quality sensitive working conditions of PCB depaneling machines. The specific calculation is as follows:

[0052] ;

[0053] in, For the first The clearance feedback degree of each candidate empty cut segment is calculated by the device controller; For the first The average spindle speed of each candidate empty cut segment, derived from the output of step one. ; The spindle reference speed set for the current machining program is read from the equipment machining parameter table; For the first The average principal spindle current of each candidate empty cut segment, derived from the output of step one. ; The cutting current threshold is calibrated during the equipment commissioning phase under stable cutting conditions and written into the controller parameter table. For the first The start time of the most recent cutting movement segment after each candidate empty cut segment is determined by... The time records of subsequent cutting segments were obtained; For the first The end time of each candidate empty cut segment is determined by... The time record of the current segment is obtained; This is the reserved recovery time required for the spindle to recover from a constrained feedback state to the target speed, which is written into the controller parameter table based on the spindle recovery test results during the equipment commissioning phase. Where... Indicates the degree to which the spindle speed is maintained. This indicates how close the current load is to the cutting load. This represents the remaining time margin after deducting the reserved recovery time; all three items are proportions or relative quantities among similar quantities, and the product is the result of their values. It can be used as a window permission judgment value. If , or If not configured, zero, or below the controller's allowable lower limit, the controller will not perform calculations. And mark the candidate fragment as an invalid parameter fragment.

[0054] The controller is calculating First, perform basic screening on the candidate segments: the knife path type of the candidate segments should belong to jump movement, dodge movement, or waiting action, and Less than ,at the same time Greater than After the basic screening is met, the controller then calculates... and will The threshold is compared with the permissible threshold in the controller parameter table. This process ensures that the permissible threshold calculation only applies to segments with basic air-cutting characteristics. It is mainly used to distinguish between "empty cut segments suitable for feedback" and "empty cut segments with insufficient recovery margin or incomplete load shedding". In actual equipment, It can be obtained through stable cutting tests. For example, select the same sheet metal, the same tool, and the same target speed for continuous cutting segments, record the typical level of the spindle current after it stabilizes, and write it into the controller parameter table in combination with the process safety margin. This can be obtained through testing the spindle's recovery to the target speed after a limited speed drop, and configured according to machine model, spindle specifications, and drive response capability. For segments that fail the basic screening, the controller does not generate a feedback window and only maintains normal spindle speed closed-loop control; for segments that pass the basic screening but... For segments below the permitted threshold, the controller records them as ordinary empty cut segments so that it can distinguish between feedback-enabled and non-feedback-enabled empty cuts in subsequent energy saving statistics.

[0055] In the tool skipping segment of a certain milling cutter-type dual-platform PCB separator, the output of step one is... This segment is recorded as a tool jump movement, and the average spindle speed of the segment meets the following requirements. The average spindle current of the segment satisfies The interval between the end of the current segment and the start of the next cutting segment satisfies Substituting into the above formula, we get... When the permitted threshold in the controller parameter table is At that time, the candidate empty cut segment is written into the set of empty cut windows that can be fed back. If another switch-cutting segment has similar speed and current conditions, but its next entry point is closer, for example... ,but If this value is below the same permissible threshold, the controller treats the segment as a normal empty cut segment. This calculation result reflects the engineering implications of this step: even in a non-cutting segment, it is only used as a window for subsequent restricted weak reverse magnetization control when the spindle speed level, load disengagement degree, and next infeed recovery margin all simultaneously meet the requirements.

[0056] The controller writes candidate empty cut segments that meet the licensing conditions. . Each window records its window number and corresponding... Segment number, window start time, window end time, average spindle speed within the window, average spindle current within the window, and air cut feedback allowance. The window start and end times are inherited from the start and end times of the corresponding spindle running segment, while the window average spindle speed and average spindle current are inherited from the average spindle speed and average spindle current of the corresponding segment. This is calculated based on the aforementioned permission level. It also saves the permission threshold version, the source of the next tool entry time, and the window validity flag; if no window meets the permission conditions in the entire machining program, then Since the set is empty, step three outputs an empty control sequence, and step four does not execute weak reverse magnetization feedback control. This results in... The stable operating boundary generated in step one is retained, and the feedback capability of each window is further indicated, serving as the input for generating the restricted weak inverse magnetization control sequence in step three.

[0057] The restricted weak reverse magnetization control quantity generation module is used to receive the set of feedback open-cut windows, convert the permissibility of each feedback open-cut window into a restricted weak reverse magnetization coefficient, and determine the control action duration by combining the window duration and the spindle recovery time, thereby generating a restricted weak reverse magnetization control quantity sequence.

[0058] The corresponding steps for this module are as follows:

[0059] Step 3 is the set of feedback-enabled empty cut windows output from Step 2. Generate a constrained weak dimagnetization control sequence . Each feedback-enabled idle cut window has recorded its window number, corresponding segment number, window start time, window end time, average spindle speed, average spindle current, and idle cut feedback allowance. This step converts this window-level information into control parameters executable by the spindle driver. For PCB depaneling machines, even segments deemed as having a feedback-capable air-cutting window exhibit differences in their executable demagnetization strength. For example, long skip windows typically have more recovery margin, while short avoidance windows require more speed recovery space. Milling cutter spindles recover speed faster during short-path jumps, while saw blade spindles, due to their larger moment of inertia, require a smoother current adjustment process. Therefore, this step... As the window admission strength, combined with the average spindle speed and average spindle current of the window, the confined weak diamagnetic coefficient corresponding to each window is generated. Then, based on the window duration and spindle recovery time... Determine the duration of the control action so that subsequent steps can execute the actual spindle feedback action according to the window difference. If Since this is an empty set, this step does not generate any actual execution control variables; it only outputs an empty set. And no feedback execution flag.

[0060] Limited weak dimagnetization coefficient The calculation originates from the proportional command mapping and saturation limiting calculation in the drive control. Step two has already combined the spindle speed level, load release degree, and the recovery margin for the next tool entry into a single calculation. This step will Converting the control ratio to an executable value for the spindle drive, the higher the window clearance, the stronger the weak demagnetization; the closer the window clearance is to the admission boundary, the weaker the weak demagnetization. The full-amplitude clearance is set in the controller parameter table. This is used to represent the permissibility reference value corresponding to when the empty cut window reaches a relatively sufficient feedback condition. This can be determined during the equipment commissioning phase based on operational records of typical long skip window, low-load no-load cut-off window, and stable recovery window. The specific calculations are as follows:

[0061] ;

[0062] in, For the first The limited weak dimagnetization coefficient corresponding to each feedback cut window is calculated by the device controller and written into the driver control parameters; The empty cut feedback permission obtained in step two comes from ; To achieve full-amplitude permissibility, the parameters are written into the controller parameter table during the equipment commissioning phase. and Derived from the lower and upper bound truncation operations in mathematics, this formula is used to limit the control ratio within the actuator's executable range. It directly maps the window permission level obtained in step two to the drive control ratio, avoiding the repeated superposition of spindle speed and spindle current factors. Step two is responsible for window permission judgment, while step three is responsible for control strength generation. If... If the value is not configured or falls below the controller's allowed lower limit, the controller will not generate a weak demagnetization execution command for that window and will mark the window state as having invalid control parameters; this avoids issues caused by missing full-width permissibility. The calculation is abnormal or the control strength is abnormal.

[0063] In obtaining Then, the controller calculates the window start time, window end time, and spindle recovery time. The duration of the weak reverse magnetization control action is determined. This time allocation relationship is derived from the event window scheduling method in motion control, which allocates the first segment of a finite time window to execute the control action and the last segment to state recovery. This application, considering the characteristics of the spindle's weak reverse magnetization control, integrates the recovery tail segment with... Related: The larger the value, the stronger the demagnetization effect, the more rotational inertia the main shaft releases, and the longer the recovery time retained at the end of the window. The smaller the value, the weaker the demagnetization effect, and the shorter the control duration can be, allowing it to be closer to the window length. The specific calculation is as follows:

[0064] ;

[0065] in, For the first The duration of weak reverse magnetization control allowed to be performed within a feedback cut-off window is calculated by the device controller. For the first The start time of a window that can provide feedback on the empty cut-off window, from ; For the first The end time of a window that can provide feedback on the empty cut-off window, from ; The above-mentioned restricted weak diamagnetic coefficient; The reserved recovery time required for the spindle to recover from the restricted feedback state to the target speed is written into the controller parameter table by the spindle recovery test results during the equipment commissioning phase. Derived from the lower bound truncation operation in mathematics, it is used to keep the duration of action within an executable range. In the formula... For window duration, The recovery protection time varies with the control intensity; both are time-related quantities, and the calculated values ​​are... The duration of weak reverse magnetization control performed by the driver. The controller sets the control start time to... Set the control end time to ;when When the value is zero, the window is only retained as a recognizable empty-cut window, and no actual weak demagnetization execution command is generated. If Not greater than If the window duration is less than the driver's minimum execution time, the controller will also not generate any actual execution instructions.

[0066] The controller then followed Generate excitation current and torque current adjustment values. For spindle drives using vector control, the excitation current channel is used to adjust the spindle motor flux linkage, and the torque current channel is used to adjust the direction of the spindle electromagnetic torque. During equipment commissioning, set the excitation current reference adjustment value and torque current reference adjustment value in the drive parameter table. The controller adjusts the value according to the specified parameters within each window. The reference adjustment value is scaled proportionally to form the actual excitation current and torque current adjustments performed within the specified window. For saw blade spindles, the driver can use a gentler current slope to write the adjustment value to accommodate the larger moment of inertia; for milling cutter spindles, the driver can use a shorter current settling time to accommodate the short tool skip window. These differences are achieved through the configuration of the reference adjustment value and current slope in the driver parameter table. It participates in execution as a unified window control coefficient. The controller writes... Before proceeding, the excitation current regulation, torque current regulation, current slope, and driver feedback capability are also checked. If they exceed the driver protection limit, the window is either truncated according to the protection limit or marked as unexecutable to avoid the control quantity exceeding the hardware capability.

[0067] In a certain milling cutter-type online dual-platform depaneling machine, the feedback-capable empty cutting window output in step two satisfies... The full-range permissibility in the controller parameter table is Substituting into the first equation, we get If the duration of the window satisfies Substituting this into the second equation, we get... The controller sets the start time of control for this window to... The control end time is set to And then enter a normal speed holding state at the end of the remaining window. For the other window, if its Lower, then Consequently, the excitation current regulation and torque current regulation decrease simultaneously; if its Reaching or exceeding ,but Restricted to The driver performs limited weak demagnetization control according to the reference adjustment allowed for this model. In the example above... and Subsequent writes In step four, these parameters are used to determine the current regulation intensity and execution duration, respectively.

[0068] Finally, the device controller generates a sequence of restricted weak reverse magnetization control quantities according to the window numbering order. . Each control variable should include at least the corresponding window number, control start time, control end time, and duration of weak reverse magnetization control. Limited weak diamagnetic coefficient Excitation current regulation and torque current regulation. Corresponding window numbers are from... The start time of control is determined by the start time of the corresponding window; the end time of control is determined by... Sure; Window duration, and spindle recovery time Determined jointly; confined weak diamagnetic coefficient Permission degree from air cut feedback and full-width permission The excitation current adjustment and torque current adjustment are calculated together and determined by the spindle drive according to... The baseline adjustment values ​​in the equipment parameter table are generated by scaling them proportionally. It also saves the parameter version number, driver protection limit verification results, and the executable flag for the window; non-executable windows do not proceed to the actual current adjustment process in step four. This will serve as the input for the spindle restricted power generation control in step four, enabling step four to complete the spindle drive energy feedback according to the control time, control duration, and current adjustment amount for each window.

[0069] The spindle drive energy feedback execution module is used to receive the restricted weak reverse magnetization control quantity sequence, and according to the control time and control duration in the control sequence, send the excitation current adjustment quantity and torque current adjustment quantity to the spindle driver to make the spindle enter the restricted power generation state. At the end of the window, the feedback effect is gradually converged according to the spindle speed protection boundary to feed the rotational inertia back to the DC bus.

[0070] Step four follows the constrained weak demagnetization control sequence output in step three. Perform spindle drive energy feedback. Each control variable already includes the corresponding window number, control start time, control end time, and restricted weak diamagnetic coefficient. The excitation current regulation and torque current regulation are adjusted in sequence, and control commands are sent to the spindle driver window by window. When the system time reaches the start time of a certain window, the controller reads the corresponding excitation current regulation and torque current regulation for that window and gradually loads them into the excitation current channel and torque current channel according to the current ramp writing method inside the driver. The excitation current regulation causes the spindle motor flux linkage to shift in the direction of field weakening, and the torque current regulation causes the spindle to generate a restricted reverse electromagnetic torque. The spindle enters a restricted power generation state from the normal speed holding state, and the rotational inertia is fed back to the DC bus through the spindle driver. For milling cutter spindles, a shorter ramp can be used in the current build-up process to accommodate the short tool jump window; for saw blade spindles, a gentler ramp can be used in the current build-up process to accommodate the larger rotational inertia and more obvious disc vibration characteristics. The above ramp parameters are given by the driver parameter table. Provide the execution boundaries and adjustment strength for each window to ensure that the control actions are consistent with the window control variables generated in step three. If the window is empty, marked as non-executable, the spindle drive is in a fault state, the emergency stop signal is valid, the DC bus voltage is close to the overvoltage protection threshold, or the next cutting segment arrives early, the controller will not execute the weak demagnetization command for that window and will maintain normal speed closed-loop or drive protection control.

[0071] During window execution, the controller reads the actual spindle speed in real time. And based on the current window Dynamic convergence is achieved for weak reverse magnetization. This control relationship originates from the basic principle in motor speed closed-loop control that "the closer the speed is to the protection boundary, the smaller the reverse torque should be." This application applies this principle to the PCB depaneling machine's air-cut feedback scenario, controlling the limited weak reverse magnetization coefficient. With process allowable speed drop coefficient Combined, a speed protection boundary is formed for the current window. When the actual spindle speed approaches this boundary, the driver gradually reduces the excitation current regulation and torque current regulation, allowing the spindle to smoothly return from the restricted power generation state to the normal speed holding state. The specific calculation is as follows:

[0072] ;

[0073] in, For the first The current regulation convergence coefficient within each window is calculated by the device controller in each control cycle. The actual spindle speed during the current control cycle is read by the spindle encoder or the driver speed measurement module. The spindle reference speed set for the current machining program is read from the equipment machining parameter table; The allowable speed drop coefficient is configured from the process parameter table according to the processing requirements of the milling cutter or saw blade. The restricted weak diamagnetic coefficient generated in step three comes from... ; This is the speed offset value in the controller parameter table, used for calculating the stability of the low-intensity control window. This formula is derived from the speed lower limit judgment, where... This indicates the spindle speed protection boundary corresponding to the current window. The numerator represents the allowable range of variation between the reference speed and the protection boundary, while the numerator represents the degree to which the current actual spindle speed exceeds the protection boundary. The controller limits the calculation results to... to This allows it to be directly used as a proportional correction coefficient for the excitation current regulation and torque current regulation. If zero or If not configured, the controller will not enter restricted power generation control; if The speed has fallen below the protection limit, and the controller will immediately... Set to zero and resume normal speed holding control.

[0074] The controller multiplies the excitation current regulation and torque current regulation obtained in step three by the following: Then it is written to the spindle driver. When near When the actual spindle speed is close to the reference speed, the drive performs limited power generation according to the set intensity of the current window; when As the speed gradually decreases, the actual spindle speed approaches the protection boundary of this window, and the driver synchronously reduces the weak demagnetization effect; when Descending to When the window's weak reverse magnetization adjustment is reached, the controller stops and switches to normal speed holding control. The window execution is also constrained by the control end time; the system time is reached... After the recorded control end time, the controller cancels the excitation current adjustment and torque current adjustment according to the driver current ramp, and maintains the target speed control at the end of the window, so that the spindle is in a stable operating state before the next tool entry. Thus, step four simultaneously uses... The window number, control start time, control end time, and duration of weak reverse magnetization control are specified in the data. , The excitation current and torque current are adjusted to convert the control sequence into the actual spindle drive action. During execution, if the bus voltage exceeds the upper limit of the feedback allowable value, the feedback current exceeds the driver allowable value, or the spindle vibration or driver temperature exceeds the protection threshold, the controller will cancel the weak reverse magnetization adjustment in advance and mark the window as the protection exit window.

[0075] In a certain saw blade type online dual-platform depaneling machine, a certain window output in step three corresponds to... In the process parameter table When a control cycle reads during window execution... ,and Compared to When the value is very small, substituting it into the above formula yields... The driver maintains a high proportion of weak demagnetization; when the actual spindle speed drops to [a certain value] in subsequent control cycles... At that time, it can be obtained The driver proportionally reduces the excitation current and torque current regulation, causing the saw blade spindle to gradually exit the restricted power generation state at the tail end of the window. For milling cutter-type short jump cutter windows, due to the smaller moment of inertia and faster speed response... Changes in spindle speed can be reflected more quickly, and the drive can complete the fade-in, hold, and fade-out actions within a shorter window. In this example... This only corrects the current adjustment ratio within the current window. It will not apply to the next window after the current window closes; the next window will adjust the ratio based on the corresponding current adjustment. , The convergence coefficient is calculated using the protection boundary.

[0076] When the spindle is in a limited power generation state, the DC bus sampling circuit of the driver records the changes in bus voltage and bus feedback current, and the controller statistically analyzes the recovered electrical energy within each window. This statistical relationship is derived from the fundamental electrical relationship that electrical energy equals electrical power accumulated over time. The instantaneous DC bus feedback power is represented by the product of the bus voltage and the bus feedback current taken as positive in the feedback direction; this application limits this relationship to... The corresponding control window is used to calculate the electrical energy generated by the spindle feedback during the idle cutting window. The specific calculation is as follows:

[0077] ;

[0078] in, The electrical energy recovered from the spindle empty cutting window during this processing is accumulated by the equipment controller based on the bus sampling data of each window; For the first The start time of window control comes from ; For the first The duration of the weak demagnetization control effect in each window comes from... ; For a moment The DC bus voltage is read by the DC bus sampling circuit of the spindle driver; For a moment The DC bus feedback current is read by the spindle driver bus current sampling circuit or the driver's internal feedback current estimation module, and positively charged according to the direction of feedback to the DC bus. Where... This represents the instantaneous feedback power of the DC bus. Accumulated over the control window time, it yields the recovered energy for that window. The sum of all windows' energy is then used to obtain the recovered energy from the spindle's idle cutting during the current machining process. If the bus current direction is not the feedback direction within a certain control cycle, the controller will not include that cycle in the recovered energy count to avoid misrepresenting the driver's energy consumption as feedback energy. If the bus sampling is abnormal, the energy statistics for that window will be marked as invalid, but this will not affect the already completed speed protection control records.

[0079] Within a certain window, when the bus feedback power sampled by the driver remains at the same proportional level across multiple control cycles, the controller accumulates the above formula according to the discrete sampling period. For example, the bus voltage sampling value and feedback current sampling value of consecutive control cycles within a certain window are converted by the driver to obtain an approximately constant feedback power level, and the duration of this window is the same as that calculated in step three. The controller multiplies the power level by the corresponding control cycle length item by item and adds them up to obtain the recovered energy for that window; after multiple windows are completed, the recovered energy of each window is added together to form the total recovered energy. The equipment commissioning log can be used to compare the external power consumption and driver bus energy records before and after enabling this control, under the same toolpath, spindle speed, and material conditions. This verifies the contribution of the empty cutting window feedback control to spindle drive energy saving. To ensure effective comparison, the commissioning log also saves the toolpath file, tool type, material type, spindle reference speed, feedback control activation status, and machining cycle time, avoiding misinterpreting energy consumption differences under different operating conditions as the energy-saving effect of this control strategy.

[0080] Finally, the controller completed... After all windows are executed, the output DC bus recovers electrical energy. And the spindle operating state that meets the requirements for the next tool entry. The above bus energy statistics are used to determine the spindle operating status, which is determined by the actual spindle speed after the window ends. With spindle reference speed The approximation level is determined and maintained within the process-allowed range by the driver speed closed loop. This step completes the execution from the constrained weak reverse magnetization control quantity to the actual feedback action of the spindle, enabling the PCB depanel to convert part of the spindle rotational inertia into DC bus electrical energy within the air-cutting window, while maintaining the spindle speed required for subsequent tool entry. The controller will also... The number of protected exit windows, the number of non-executable windows, and the speed recovery result before tool entry are written into the machining record for subsequent adjustments. , , , Parameters such as these are required, but parameter updates need to be written into the parameter table after equipment debugging or process confirmation to avoid automatically relaxing safety boundaries during online processing.

[0081] This invention also provides an energy-saving control device for the spindle drive of a PCB depaneling machine based on energy feedback, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the steps described in the above embodiment of an energy-saving control system for the spindle drive of a PCB depaneling machine based on energy feedback; or, when the processor executes the computer program, it implements the functions of each module in the above system embodiments.

[0082] For example, the computer program may be divided into one or more modules, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules may be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program in the energy-saving control device for the spindle drive of a PCB depaneling machine based on energy feedback.

[0083] The energy-saving control device for the spindle drive of a PCB depaneling machine based on energy feedback can be a computing device such as a desktop computer, laptop, handheld computer, or cloud server. This energy-saving control device may include, but is not limited to, a processor and memory. Those skilled in the art will understand that the energy-saving control device may also include input / output devices, network access devices, buses, etc.

[0084] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor. This processor is the control center of the energy-saving control device for the spindle drive of a PCB depaneling machine based on energy feedback, connecting all parts of the device via various interfaces and lines.

[0085] The memory can be used to store the computer program and / or modules. The processor implements various functions of the energy-saving control device for the spindle drive of a PCB depaneling machine based on energy feedback by running or executing the computer program and / or modules stored in the memory and calling the data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function, etc.; the data storage area may store data created according to the operation of the controller, etc. In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital card (SD card), flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.

[0086] The module integrated into the PCB depaneling machine spindle drive energy-saving control device based on energy feedback, if implemented as a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above-described system embodiments can also be implemented by a computer program instructing related hardware. This computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various system embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0087] Those skilled in the art will understand that all or part of the processes in the systems described in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the embodiments of the above systems. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0088] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. An energy-saving control system for the spindle drive of a PCB depaneling machine based on energy feedback, characterized in that, The system includes: The spindle running segment generation module is used to read the toolpath segment type in the local toolpath file and simultaneously read the actual spindle speed and spindle current. When the changes in toolpath segment type and spindle current both meet the stability conditions, it generates a spindle running segment sequence with stable load boundaries. The feedback empty cutting window determination module is used to receive the spindle running segment sequence and determine the feedback empty cutting window set from the spindle running segment sequence based on the toolpath segment type, spindle speed maintenance degree, load release degree and recovery margin before the next tool entry; The restricted weak reversible magnetization control quantity generation module is used to receive the set of feedback open-cut windows, convert the permissibility of each feedback open-cut window into a restricted weak reversible magnetization coefficient, and determine the control action duration by combining the window duration and the spindle recovery time, thereby generating a restricted weak reversible magnetization control quantity sequence. The spindle drive energy feedback execution module is used to receive the restricted weak reverse magnetization control quantity sequence, and according to the control time and control duration in the control sequence, send the excitation current adjustment quantity and torque current adjustment quantity to the spindle driver to make the spindle enter the restricted power generation state. At the end of the window, the feedback effect is gradually converged according to the spindle speed protection boundary to feed the rotational inertia back to the DC bus.

2. The PCB depaneling machine spindle drive energy-saving control system based on energy feedback according to claim 1, characterized in that, The spindle running segment generation module is specifically used for: The toolpath timing, spindle speed sampling, and spindle current sampling are aligned using a unified timestamp. Calculate the relative change value of the spindle current in adjacent sampling periods. When the tool path segment type remains unchanged and the relative change value of the spindle current is less than the preset stability threshold in several consecutive sampling periods, the current spindle load is confirmed to be stable, and the stable starting point is taken as the effective starting position of the spindle running segment. When the toolpath segment type is switched, or when the relative change value of the spindle current continuously exceeds the preset stable threshold, the current segment ends, forming a spindle running segment sequence arranged in the order of processing time.

3. The PCB depaneling machine spindle drive energy-saving control system based on energy feedback according to claim 1, characterized in that, The feedback-enabled empty cut-off window determination module is specifically used for: Candidate air cut segments with toolpath types of jump movement, avoidance movement, or waiting action are selected from the spindle running segment sequence; The air-cut feedback allowance of the candidate air-cut segment is calculated. The air-cut feedback allowance is a comprehensive judgment value based on the ratio of the average spindle speed of the segment to the reference speed, the ratio of the average spindle current of the segment to the cutting current threshold, and the time margin from the end of the segment to the start of the next cutting. Candidate empty cut segments with an empty cut feedback permission degree greater than the permission threshold are written into the set of empty cut windows that can receive feedback.

4. The PCB depaneling machine spindle drive energy-saving control system based on energy feedback according to claim 1, characterized in that, The restricted weak reverse magnetization control quantity generation module is specifically used for: The permissibility of the permissible ... The reserved recovery time at the end of the window is adjusted according to the restricted weak dimagnetization coefficient, and the duration of weak dimagnetization control allowed to be performed within the window is calculated. The preset reference adjustment amount is scaled proportionally according to the restricted weak reverse magnetization coefficient to generate the excitation current adjustment amount and torque current adjustment amount corresponding to each window.

5. The PCB depaneling machine spindle drive energy-saving control system based on energy feedback according to claim 4, characterized in that, The restricted weak reverse magnetization control quantity generation module is also specifically used for: Verify the excitation current regulation, torque current regulation, and driver feedback capability. If the driver protection limit is exceeded, mark the window as an unexecutable window. The restricted weak reverse magnetization control quantity sequence includes the corresponding window number, control start time, control end time, weak reverse magnetization control duration, restricted weak reverse magnetization coefficient, excitation current adjustment quantity, and torque current adjustment quantity.

6. The PCB depaneling machine spindle drive energy-saving control system based on energy feedback according to claim 1, characterized in that, The spindle drive energy feedback execution module is specifically used for: When the control start time arrives, the excitation current regulation and torque current regulation in the restricted weak reverse magnetization control quantity sequence are read, and applied to the excitation current channel and torque current channel of the spindle driver according to the preset current ramp, so that the spindle enters the restricted power generation state from the speed holding state.

7. The PCB depaneling machine spindle drive energy-saving control system based on energy feedback according to claim 6, characterized in that, The spindle drive energy feedback execution module is also specifically used for: The actual spindle speed is read in real time, and the current regulation convergence coefficient is calculated. The current regulation convergence coefficient is determined based on the relative relationship between the actual spindle speed and the speed protection boundary. The excitation current regulation and torque current regulation are multiplied by the current regulation convergence coefficient and then written into the spindle driver, so that the spindle can smoothly exit the restricted power generation state when it approaches the speed protection boundary.

8. The PCB depaneling machine spindle drive energy-saving control system based on energy feedback according to claim 7, characterized in that, The speed protection boundary is determined by the spindle reference speed set in the current machining program and the process allowable speed drop coefficient. When the actual spindle speed is lower than the speed protection boundary, the current regulation convergence coefficient is immediately set to zero and normal speed maintenance control is restored.

9. The PCB depaneling machine spindle drive energy-saving control system based on energy feedback according to claim 1, characterized in that, The spindle drive energy feedback execution module is also specifically used for: After the control duration ends or the system time reaches the control end time, the excitation current adjustment and torque current adjustment are canceled according to the current ramp, and the target speed control is maintained at the end of the window to ensure that the spindle is in a stable operating state before the next cut.

10. The PCB depaneling machine spindle drive energy-saving control system based on energy feedback according to claim 1, characterized in that, It also includes an energy statistics module, which is used to accumulate the product of DC bus voltage and DC bus feedback current over time during the period when the spindle is in a limited power generation state, so as to obtain the spindle air cutting recovery energy of this machining process.

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