Active control guide wheel system and method of photovoltaic diamond wire slicing machine

Abstract

The invention relates to the technical field of photovoltaic slicing equipment control, in particular to an active control guide wheel system and method for a photovoltaic diamond wire slicer, and the system comprises a left wire wheel and a right wire wheel which are respectively used for winding and unwinding a diamond wire; the plurality of guide wheels are arranged between the left wire wheel and the right wire wheel; the servo motor driving unit comprises a servo motor which is independently equipped for each guide wheel; the tension monitoring unit is used for collecting tension data of the diamond wire in real time and feeding back the tension data to the central controller; the main shaft motor is used for driving the cutting main shaft to rotate and providing main shaft linear velocity data for the central controller; the take-up and pay-off motor drives the left wire wheel and the right wire wheel to achieve take-up and pay-off movement of the diamond wire. And the central controller is in communication connection with the servo motor driving unit, the main shaft motor and the take-up and pay-off motor, and is used for adjusting the rotating speed of each guide wheel by adopting a high-dynamic PID control algorithm based on the diamond wire tension data acquired by the tension monitoring unit in real time.

Description

Technical Field

[0001] This application relates to the field of photovoltaic slicing equipment control technology, and in particular to an active control guide wheel system and method for a photovoltaic diamond wire slicing machine. Background Technology

[0002] With the rapid development of the photovoltaic industry, silicon wafer manufacturing processes are constantly evolving towards higher precision, higher stability, and higher efficiency. Diamond wire slicing machines, as key equipment in the silicon wafer production process, directly affect the thickness uniformity, cutting quality, and yield of the wafers. In existing diamond wire cutting equipment, the diamond wire typically needs to be guided through multiple guide rollers, with the left and right rollers controlling the wire feeding and take-up actions, maintaining stable wire speed and tension during the high-speed rotation of the cutting spindle. However, traditional guide roller mechanisms mostly employ mechanical linkage or single drive methods, resulting in insufficient dynamic response capabilities between the guide rollers. This can easily lead to tension fluctuations and wire speed mismatches during high-speed cutting, resulting in quality defects such as edge chipping, deepened wire marks, and increased thickness deviations in the silicon wafers.

[0003] In typical traditional solutions, diamond wire tension adjustment relies primarily on a single-point tension control mechanism. By detecting tension changes at a specific location, the speed of the take-up and untake-up motors is adjusted to indirectly balance the forces on the guide wheel system. However, this control method places extremely high demands on system real-time performance. Furthermore, due to the lack of independent drive capability and controllability among the guide wheels, the tension response path is excessively long, resulting in significant lag in tension adjustment. When the spindle accelerates, decelerates, switches operating conditions, or experiences large changes in the inertia of the wire wheels, the system often cannot compensate for tension disturbances in a timely manner, leading to transient tension peaks or tension collapses in the cutting zone. In addition, relying solely on mechanical linkage for speed transmission among multiple guide wheels can cause cumulative errors when there is wear, misalignment, or slight resistance differences in the guide wheels. This causes a deviation between the actual and theoretical diamond wire trajectory, directly affecting cutting stability. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, this application provides an active control guide wheel system and method for a photovoltaic diamond wire slicing machine, which solves the technical problems of unstable cutting caused by the inability of the existing guide wheel to adjust its speed independently and the lack of an active matching mechanism for changes in the speed of the main axis.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the main technical solutions adopted in this application include:

[0008] This application provides an active control guide wheel system for a photovoltaic diamond wire slicing machine, including:

[0009] The left and right reels are used for loading and unloading diamond wire, respectively.

[0010] Multiple guide rollers are disposed between the left wire roller and the right wire roller, and the multiple guide rollers include at least an inlet wire guide roller, an inlet tension control guide roller, a cutting roller inlet guide roller, a cutting roller outlet guide roller, an outlet tension control guide roller, and an outlet wire guide roller;

[0011] The servo motor drive unit includes a servo motor independently equipped for each of the following guide wheels: the wire feeding guide wheel, the wire feeding tension control guide wheel, the cutting roller wire feeding guide wheel, the cutting roller wire output guide wheel, the wire output tension control guide wheel, and the wire output guide wheel.

[0012] The tension monitoring unit is used to collect diamond wire tension data in real time and feed the tension data back to the central controller;

[0013] The spindle motor drives the cutting spindle to rotate and provides spindle speed data to the central controller;

[0014] The take-up and release motors drive the left and right reels respectively to realize the take-up and release of the diamond wire;

[0015] The central controller is communicatively connected to the servo motor drive unit, the spindle motor, and the take-up and unwind motor. It is used to adjust the rotational speed of each guide wheel based on the diamond wire tension data collected in real time by the tension monitoring unit, using a high-dynamic PID control algorithm.

[0016] Preferably, in some embodiments of this application, the system further includes: a security protection module; the security protection module includes:

[0017] The rotational speed detection unit is used to detect the rotational speed of each guide wheel in real time;

[0018] An anomaly detection unit is used to compare the rotational speed of each guide wheel detected by the rotational speed detection unit with a preset rotational speed threshold, and to determine whether the rotational speed deviation of any guide wheel exceeds the preset threshold.

[0019] The protection execution unit is used to send an emergency braking command to the central controller when the speed deviation of any guide wheel exceeds the preset threshold.

[0020] The central controller is also used to control the servo motor drive unit, spindle motor and take-up / unwind motor to stop rotating sequentially according to a preset safe stopping sequence after receiving the emergency braking command.

[0021] Preferably, in some embodiments of this application, based on the diamond wire tension data collected in real time by the tension monitoring unit, a high-dynamic PID control algorithm is used to adjust the rotational speed of each guide wheel, specifically including:

[0022] Based on the real-time diamond wire tension data collected by the tension monitoring unit, the tension deviation value ΔT at each guide wheel is obtained. The tension deviation value ΔT is the difference between the actual measured diamond wire tension and the preset target tension.

[0023] The tension deviation value ΔT is input into the high dynamic PID control algorithm to calculate the target speed correction amount Δn for each guide wheel.

[0024] Based on the linear velocity signal V0 provided by the spindle motor, the target speed correction amount Δn is superimposed to form the real-time target linear velocity V = V0 + Δn for each guide wheel;

[0025] The rotational speed output of the servo motor of each guide wheel in the servo motor drive unit is controlled so that the guide wheel on the servo motor achieves the real-time target linear velocity.

[0026] Preferably, in some embodiments of this application, the tension deviation value ΔT is input into a high dynamic PID control algorithm to calculate the target speed correction amount Δn for each guide wheel, specifically including:

[0027] The tension deviation value is used as the input to the closed-loop control, and the control action is calculated using a high-dynamic PID control algorithm; the PID control algorithm includes proportional, integral, and derivative actions.

[0028] The proportional control function generates a control action that is proportional to the current tension deviation value.

[0029] The integral function is to integrate the historical tension deviation;

[0030] The differential action is used to predict the rate of change of tension deviation;

[0031] The control input is converted into a target linear velocity correction for each guide wheel.

[0032] Preferably, in some embodiments of this application, the control action quantity is converted into the target linear velocity correction quantity of each guide wheel, specifically by converting the control action quantity into the target linear velocity correction quantity of each guide wheel through a conversion formula;

[0033] The conversion formula is: ΔV(t) = Kt × u(t);

[0034] Where ΔV(t) is the linear velocity correction of the guide wheel, Kt is the pre-set tension-velocity sensitivity coefficient, and u(t) is the control action.

[0035] Preferably, in some embodiments of this application, the high dynamic PID control algorithm further includes feedforward compensation, which is used to adjust the linear speed of each guide wheel in advance according to known disturbances in the system, the disturbances including: acceleration information of the spindle motor and the take-up and unwind motor;

[0036] The feedforward compensation and the PID closed-loop control output are superimposed to form the control action of each guide wheel.

[0037] Preferably, in some embodiments of this application, the bearing of the guide wheel is a high-temperature resistant bearing.

[0038] Preferably, in some embodiments of this application, the servo motor of the servo motor drive unit is a high dynamic response servo motor, with a torque response time of less than 1ms and an overload capacity of more than 3 times the rated torque.

[0039] Preferably, in some embodiments of this application, the guide wheel is made of a lightweight material; the surface of the guide wheel is coated with a friction-reducing and wear-resistant coating.

[0040] On the other hand, embodiments of this application also provide an active control guide wheel method for a photovoltaic diamond wire slicing machine, the method being executed by the aforementioned active control guide wheel system for the photovoltaic diamond wire slicing machine.

[0041] (III) Beneficial Effects

[0042] The active control guide wheel system and method for a photovoltaic diamond wire slicing machine provided in this application embodiment features an independently configured servo motor for each guide wheel, with speed coordinated and adjusted by a central controller. This allows the wire feeding guide wheel, wire tension control guide wheel, cutting roller wire feeding guide wheel, cutting roller wire exit guide wheel, wire exit tension control guide wheel, and wire exit guide wheel to dynamically adjust their speeds based on real-time tension data, fundamentally avoiding the problem of slow response to tension disturbances in traditional mechanical guide wheels. Furthermore, by continuously collecting diamond wire tension data through a tension monitoring unit and combining it with a high-dynamic PID control algorithm, the central controller can quickly respond to tension deviations and perform fine-grained compensation adjustment of the rotational speed of each guide wheel, thereby achieving real-time closed-loop control of diamond wire tension and effectively suppressing instantaneous tension fluctuations caused by changes in operating conditions. Furthermore, the system uses the spindle motor's output spindle speed as the core reference, and matches the linear speed of the take-up and untake-up motors and all guide rollers through a central controller. This ensures that the movement of the diamond wire remains continuous, coordinated, and stable throughout the take-up, untake-up, and cutting paths, thereby reducing the risk of uneven wear, jumping, and wire breakage caused by excessive speed differences in the diamond wire. Therefore, the system described in this application has significant technical effects in ensuring the stability of the slicing process, improving cutting accuracy, extending the service life of the diamond wire, and reducing equipment downtime. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the connection of the central controller in the active control guide wheel system of a photovoltaic diamond wire slicing machine according to an embodiment of this application;

[0044] Figure 2This is a schematic diagram of the guide wheel structure of the active control guide wheel system of a photovoltaic diamond wire slicing machine according to an embodiment of this application. Detailed Implementation

[0045] To better explain and facilitate understanding of this application, the following detailed description of the application is provided in conjunction with the accompanying drawings and specific embodiments.

[0046] In related technologies, the tension control and linear speed coordination of photovoltaic diamond wire slicing machines can be mainly summarized into two approaches:

[0047] The first type is the traditional passive tension control scheme that relies on the take-up and untake-up motor for overall speed adjustment. This type of scheme typically maintains the tension of the diamond wire within an acceptable range along the cutting path by adjusting the take-up or untake-up speed of the left or right wire reel. However, because the take-up and untake-up motor only acts on the entire wire segment, its adjustment granularity is coarse, its response speed is slow, and it cannot provide local compensation for tension differences at different points along the wire entry and exit paths. When the cutting spindle accelerates or decelerates, the local hardness of the silicon ingot changes, or the friction coefficient of the guide roller fluctuates, the tension of the diamond wire will shift instantaneously. The single-point adjustment of the take-up and untake-up motor cannot offset this disturbance in real time, resulting in large tension fluctuations, wire speed mismatch, uneven cutting texture, and even the risk of wire breakage.

[0048] The second type is a passive guide wheel structure (such as a free-rotating guide wheel or an air-bearing guide wheel) for buffering. This approach attempts to reduce tension fluctuations through the mechanical compliance of the guide wheel. However, since the guide wheel itself lacks active speed regulation capability, it can only passively absorb tension disturbances and cannot provide effective dynamic compensation. When the diamond wire is subjected to instantaneous tension impacts caused by changes in spindle speed, silicon ingot agitation, or uneven wire arrangement, the passive guide wheel exhibits a hysteresis response and cannot help the system return to a balanced state. Over time, guide wheel wear can cause frictional instability, further amplifying tension oscillations and reducing cutting accuracy.

[0049] To address this, the active control guide wheel system of the photovoltaic diamond wire slicing machine provided in this application introduces full-path multi-point servo active drive into the guide wheel structure. This allows the wire feeding guide wheel, wire tension control guide wheel, cutting roller wire feeding guide wheel, cutting roller wire exit guide wheel, wire exit tension control guide wheel, and wire exit feeding guide wheel to all be driven by independent servo motors, achieving precise local speed adjustment of the diamond wire at different positions. A tension monitoring unit collects diamond wire tension data in real time, and a central controller uses a high-dynamic PID algorithm to perform closed-loop compensation on the rotational speed of each guide wheel, eliminating tension disturbances within milliseconds. By accessing the spindle motor's spindle speed data, each guide wheel and the take-up and untake-down motor maintain dynamic synchronous adjustment matching the spindle speed throughout the cutting process. Thus, regardless of whether the instantaneous tension disturbances are caused by differences in silicon ingot material, changes in wire feeding speed, or spindle acceleration and deceleration, the system can achieve real-time response and stable control throughout the entire path, significantly improving cutting uniformity, reducing wire breakage rate, increasing processing yield, and making the overall control process more stable, reliable, and precise.

[0050] To better understand the above technical solutions, exemplary embodiments of this application will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this application can be understood more clearly and thoroughly, and that the scope of this application can be fully conveyed to those skilled in the art.

[0051] Figure 1 This is a schematic diagram showing the connection of the central controller in the active control guide wheel system of a photovoltaic diamond wire slicing machine according to an embodiment of this application. The active control guide wheel system of the photovoltaic diamond wire slicing machine includes:

[0052] The left and right reels are used for loading and unloading diamond wire, respectively.

[0053] Multiple guide wheels are arranged between the left and right spools, such as... Figure 2 As shown, the plurality of guide rollers includes at least an inlet guide roller 1, an inlet tension control guide roller 2, a cutting roller inlet guide roller 3, a cutting roller outlet guide roller 4, an outlet tension control guide roller 5, and an outlet guide roller 6;

[0054] The servo motor drive unit includes a servo motor independently equipped for each of the following guide wheels: wire feeding guide wheel 1, wire feeding tension control guide wheel 2, cutting roller wire feeding guide wheel 3, cutting roller wire output guide wheel 4, wire output tension control guide wheel 5, and wire output guide wheel 6.

[0055] The tension monitoring unit is used to collect diamond wire tension data in real time and feed the tension data back to the central controller;

[0056] The spindle motor drives the cutting spindle to rotate and provides spindle speed data to the central controller;

[0057] The take-up and release motors drive the left and right reels respectively to realize the take-up and release of the diamond wire;

[0058] like Figure 1 As shown, the central controller is communicatively connected to the servo motor drive unit, the spindle motor, and the take-up and unwind motor. It is used to adjust the rotational speed of each guide wheel based on the diamond wire tension data collected in real time by the tension monitoring unit, using a high-dynamic PID control algorithm.

[0059] Specifically, based on the diamond wire tension data collected in real time by the tension monitoring unit, a high-dynamic PID control algorithm is used to adjust the rotational speed of each guide wheel, including:

[0060] Based on the real-time diamond wire tension data collected by the tension monitoring unit, the tension deviation value ΔT at each guide wheel is obtained. The tension deviation value ΔT is the difference between the actual measured diamond wire tension and the preset target tension.

[0061] The tension deviation value ΔT is input into the high dynamic PID control algorithm to calculate the target speed correction amount Δn for each guide wheel.

[0062] Based on the linear velocity signal V0 provided by the spindle motor, the target speed correction amount Δn is superimposed to form the real-time target linear velocity V = V0 + Δn for each guide wheel;

[0063] The rotational speed output of the servo motor of each guide wheel in the servo motor drive unit is controlled so that the guide wheel on the servo motor achieves the real-time target linear velocity.

[0064] Specifically, the active control guide wheel system of the photovoltaic diamond wire slicing machine in this embodiment can be described through actual working conditions. Assume the slicing machine is cutting a 156mm × 156mm silicon ingot, and the real-time linear speed of the spindle motor is V0 = 1200mm / s. When the surface hardness of the silicon ingot fluctuates locally, the cutting resistance of the diamond wire changes accordingly, causing instantaneous tension fluctuations on both the inlet and outlet sides. For example, assuming that at the inlet tension control guide wheel position, the actual tension value measured in real time by the tension monitoring unit drops to 9.2N, while the preset target tension is 10N, then the tension deviation value ΔT = −0.8N can be obtained; simultaneously, at the outlet guide wheel of the cutting roller, the monitored actual tension increases to 11.1N, corresponding to ΔT = +1.1N.

[0065] After the aforementioned deviation occurs, the system inputs the tension deviation value ΔT at each position into the high-dynamic PID control algorithm. The PID control algorithm uses the proportional term K... P Integral term K I and differential term KD The combined effect of these factors allows for the calculation of the corresponding target speed correction Δn for each guide wheel. For example, for the infeed tension control guide wheel, due to the low tension, the PID control algorithm outputs Δn = +35 mm / s, slightly increasing the linear speed of the guide wheel to actively compensate for the tension of the diamond wire; while for the cutting roller outlet guide wheel, due to the high tension, the PID control algorithm outputs Δn = −42 mm / s, slightly slowing down its linear speed to help reduce the local tensile force on the diamond wire.

[0066] Subsequently, the system updates the target linear velocity of each guide wheel in real time according to V = V0 + Δn. For example, the real-time target linear velocity of the feed tension control guide wheel becomes V1 = 1200 + 35 = 1235 mm / s; the real-time target linear velocity of the cutting roller output guide wheel becomes V2 = 1200 - 42 = 1158 mm / s; other guide wheels calculate their respective Δn according to ΔT corresponding to their positions, achieving full-path synchronization and coordination. The central controller then sends the above real-time target linear velocity command to each servo motor drive unit, causing the servo motor of each guide wheel to immediately adjust its output speed, thereby enabling the guide wheel to run at the latest target linear velocity, achieving dynamic flexible tension compensation with millisecond-level response.

[0067] This example demonstrates that the active control guide wheel system of this application, through multi-point independent servo active drive and high-dynamic PID closed-loop tension control, forms a full-path, real-time, and precise tension adjustment mechanism. Since tension deviations are detected, calculated, and compensated at different guide wheel positions, the tension transmission lag problem caused by traditional single-point adjustment is effectively avoided, achieving true segmented autonomous stable control. Furthermore, the speed correction of each guide wheel is based on the spindle speed, ensuring the overall linear speed consistency of the system and maintaining a stable and uniform stress state for the diamond wire throughout the cutting path. This active control method not only quickly suppresses tension fluctuations under unstable conditions such as sudden changes in silicon ingot hardness, spindle acceleration and deceleration, and wire speed disturbances, effectively reducing the risk of wire breakage caused by instantaneous stretching, but also significantly improves the flatness and thickness uniformity of the cut wafer, increasing cutting quality and silicon wafer yield. Moreover, due to the system's high real-time and dynamic capabilities, it can still maintain tension stability in high-speed cutting scenarios, achieving both slicing efficiency and stability, and possessing superior industrial application value.

[0068] In this embodiment of the application, the tension deviation value ΔT is input into the high dynamic PID control algorithm to calculate the target speed correction amount Δn for each guide wheel, specifically including:

[0069] The tension deviation value is used as the input to the closed-loop control, and the control action is calculated using a high-dynamic PID control algorithm; the PID control algorithm includes proportional, integral, and derivative actions.

[0070] The proportional control function generates a control action that is proportional to the current tension deviation value.

[0071] The integral function is to integrate the historical tension deviation;

[0072] The differential action is used to predict the rate of change of tension deviation;

[0073] The control input is converted into a target linear velocity correction for each guide wheel.

[0074] Preferably, in this embodiment of the application, the control action quantity is converted into the target linear velocity correction quantity of each guide wheel, specifically by converting the control action quantity into the target linear velocity correction quantity of each guide wheel through a conversion formula;

[0075] The conversion formula is: ΔV(t) = Kt × u(t);

[0076] Where ΔV(t) is the linear velocity correction of the guide wheel, Kt is the pre-set tension-velocity sensitivity coefficient, and u(t) is the control action.

[0077] Specifically, in this embodiment, the tension deviation value ΔT is input into a high-dynamic PID control algorithm to calculate the target speed correction amount Δn for each guide wheel. The specific processing flow is as follows: First, the real-time measured tension deviation value ΔT is used as the closed-loop control input to the PID controller. The high-dynamic PID control algorithm consists of three parts: proportional (P), integral (I), and derivative (D). The proportional action generates a control action proportional to the current tension deviation value, enabling the system to respond quickly to instantaneous tension changes. The integral action eliminates steady-state errors by accumulating and integrating historical tension deviations, preventing the diamond wire tension from continuously deviating from the target value during long-term operation. The derivative action predicts future trends based on the rate of change of tension deviation, thereby taking compensation measures in advance, which helps to suppress overshoot caused by rapid fluctuations and improve the dynamic stability of the system. The high dynamic PID control algorithm integrates the three actions to generate the control action u(t), and then converts the control action into the target linear velocity correction amount ΔV(t) of each guide wheel, that is, ΔV(t)=Kt×u(t), where Kt is a pre-set tension-velocity sensitivity coefficient.

[0078] For example, when the tension measured in real time at the wire feed tension control guide wheel drops instantaneously from the target value of 10N to 9.4N, the tension deviation value ΔT = −0.6N can be obtained. After receiving this deviation value, the PID control algorithm immediately generates a positive control action proportional to the deviation, increasing the guide wheel's linear speed to compensate for the tension; the integral term accumulates the continuously low trend, further strengthening the driving ability for tension recovery; if the deviation changes rapidly, the derivative term predicts the tension decrease trend in advance, thereby preventing the diamond wire from continuing to slack. Assuming the PID control algorithm outputs a control action u(t) = 28, which is converted via ΔV(t) = Kt × u(t), and Kt = 1.2, the linear speed correction of the wire feed guide wheel is ΔV(t) = 33.6 mm / s. After being superimposed on the spindle reference speed, the wire feed guide wheel can promptly increase its linear speed to actively compensate for the tension of the diamond wire. Conversely, when the tension at the lead wire tension control guide wheel is too high, for example, when the tension rises to 11.3N corresponding to ΔT=+1.3N, the PID control algorithm outputs a negative control action, causing the lead wire guide wheel to slightly reduce its linear velocity, thereby reducing the local tensile force and ultimately achieving tension balance.

[0079] Through the aforementioned PID control and linear velocity correction ΔV(t) calculation process, it can be ensured that the system responds independently to tension fluctuations at different guide wheel positions, allowing each segment of the diamond wire path to receive the most suitable speed adjustment command. Since the control action u(t) undergoes a linear sensitive transformation through Kt, the tension-speed adjustment relationship more closely matches the elastic characteristics of the actual diamond wire-guide wheel system, thereby significantly improving adjustment accuracy and dynamic adaptability.

[0080] Based on the aforementioned control mechanism, the high dynamic response capability of the PID controller enables the system to quickly suppress tension fluctuations under highly dynamic conditions such as sudden changes in silicon ingot hardness, spindle acceleration and deceleration, and wire winding speed disturbances, effectively reducing the risk of wire breakage caused by excessive instantaneous tension. On the other hand, since each guide wheel is independently corrected in real time via ΔV(t), synchronous and coordinated adjustment throughout the entire path can be achieved, avoiding the tension lag and uneven transmission problems caused by traditional single-point tension adjustment, thus maintaining a more stable and uniform stress state for the diamond wire throughout the cutting path. Furthermore, utilizing the linear mapping method of ΔV(t) = Kt × u(t), the conversion of control action on speed has a clear physical meaning. Adjusting Kt can easily match different wire diameters, guide wheel materials, winding paths, and other operating conditions, thereby achieving better system adaptability. Ultimately, this embodiment significantly improves slicing uniformity, surface smoothness, and product yield, simultaneously enhancing slicing efficiency and reliability, demonstrating outstanding industrial application value.

[0081] Specifically, the high dynamic PID control algorithm also includes feedforward compensation, which is used to adjust the linear velocity of each guide wheel in advance according to known disturbances in the system. The disturbances include the acceleration information of the spindle motor and the take-up and unwind motor. The feedforward compensation is superimposed with the PID closed-loop control output to form the control action of each guide wheel.

[0082] In detail, in this embodiment, the high-dynamic PID control algorithm further includes feedforward compensation, which is used to adjust the linear speed of each guide wheel in advance based on known disturbances in the system, thereby enhancing the dynamic response capability of the system. The known disturbances mainly include the acceleration information of the spindle motor and the take-up / release motor. When the slicing machine starts, accelerates, or decelerates, the speeds of the spindle motor and the take-up / release motor change. If only traditional closed-loop PID control is relied upon, the diamond wire tension will lag, leading to excessive local stretching or slack, thus increasing the risk of wire breakage. Feedforward compensation predicts these disturbances in advance and adds the corresponding linear speed correction to the control commands of each guide wheel, achieving active control of tension. For example, suppose that when slicing a 156mm × 156mm silicon ingot, the spindle motor is accelerating from 1200mm / s to 1250mm / s, and the take-up / release motor is also accelerating synchronously to maintain the balance of diamond wire take-up and release. The system obtains the acceleration information of the spindle and the take-up / release motor through sensors and calculates the feedforward speed correction for each guide wheel based on a preset feedforward gain coefficient. For example, the feedforward correction of the infeed tension control guide wheel at this stage is +20 mm / s, and that of the cutting roller exit guide wheel is −18 mm / s. This feedforward speed correction is directly superimposed on the PID closed-loop control output ΔV(t), forming the final guide wheel control action. This allows each guide wheel to adjust its linear speed in advance during changes in the speed of the spindle and take-up / unwinding motors, actively suppressing tension fluctuations caused by acceleration. Through the superposition of feedforward compensation and high-dynamic PID closed-loop control, the embodiments of this application can achieve tension pre-adjustment and real-time correction throughout the entire path. For example, in the case of local fluctuations in silicon ingot hardness or transient conditions of spindle acceleration and deceleration, the guide wheels no longer passively wait for tension deviations to occur, but can adjust in advance based on known disturbances. The infeed and exit guide wheels can be finely adjusted in the directions of +ΔV feedforward and −ΔV feedforward, respectively, keeping the diamond wire tension close to the preset target value. As a result, the diamond wire maintains a more stable and uniform stress state throughout the cutting process, and even in high-speed cutting scenarios, it can significantly reduce the risk of wire breakage caused by instantaneous tension fluctuations. Furthermore, this feedforward compensation mechanism, combined with closed-loop PID control, enhances the system's anti-interference capability and dynamic response speed. Since the feedforward amount is calculated based on the actual motor acceleration, it can accurately match the dynamic changes of the spindle and the take-up / unwinding lines, reducing over-adjustment or lag compensation in the closed-loop PID, effectively reducing oscillation and overshoot, improving the thickness uniformity and surface flatness of the diced wafers, and increasing silicon wafer yield and production efficiency. In summary, the superimposed control of feedforward compensation and PID closed-loop enables the active control guide wheel system of this embodiment to maintain high stability and precision under high-speed, complex dynamic conditions, demonstrating significant industrial application value.

[0083] Preferably, in some embodiments of this application, the system further includes: a security protection module; the security protection module includes:

[0084] The rotational speed detection unit is used to detect the rotational speed of each guide wheel in real time;

[0085] An anomaly detection unit is used to compare the rotational speed of each guide wheel detected by the rotational speed detection unit with a preset rotational speed threshold, and to determine whether the rotational speed deviation of any guide wheel exceeds the preset threshold.

[0086] The protection execution unit is used to send an emergency braking command to the central controller when the speed deviation of any guide wheel exceeds the preset threshold.

[0087] The central controller is also used to control the servo motor drive unit, spindle motor and take-up / unwind motor to stop rotating sequentially according to a preset safe stopping sequence after receiving the emergency braking command.

[0088] For example, when cutting a 156mm × 156mm silicon ingot, the linear speed of the infeed tension control guide roller and the cutting roller output guide roller is usually maintained at around 1200mm / s. However, during the actual cutting process, if there is a motor drive failure, servo motor malfunction, or unexpected obstruction of the diamond wire, the actual rotational speed of a certain guide roller may suddenly deviate from the set value, for example, dropping to 1000mm / s or unexpectedly rising to 1400mm / s. The anomaly detection unit compares the real-time data collected by the rotational speed detection unit with the preset rotational speed threshold to determine whether there is an abnormal deviation. If the rotational speed deviation of a certain guide roller exceeds the threshold (e.g., ±50mm / s), the system immediately identifies it as a potential risk. In this way, the system can promptly detect potential dangers when tension compensation closed-loop failure or servo motor failure causes abnormal linear speed, avoiding diamond wire breakage or damage to the silicon ingot cutting process.

[0089] When the protection execution unit detects an anomaly, it sends an emergency braking command to the central controller. Upon receiving this command, the central controller sequentially stops the servo motor drive unit, spindle motor, and take-up / delivery motors according to a preset safe shutdown sequence. For example, if the lead-out guide wheel suddenly accelerates to 1400 mm / s due to a sensor malfunction, the system detects the anomaly through the protection module. The central controller immediately instructs the servo motors of the lead-out guide wheels to stop first, then gradually decelerates the spindle motor, and finally controls the left and right take-up / delivery motors to slowly stop, thus preventing excessive tension of the diamond wire or breakage of the silicon ingot due to vibration caused by a sudden shutdown. Through this mechanism, the speed detection unit provides real-time monitoring of the guide wheel speed throughout the entire path, enabling any abnormal changes to be quickly captured. Secondly, the anomaly judgment unit quickly identifies anomalies by setting thresholds, ensuring timely protection response. Finally, the protection execution unit coordinates with the central controller to execute safety measures according to a scientific shutdown sequence, effectively preventing diamond wire breakage, silicon ingot damage, or mechanical impact caused by emergency shutdown.

[0090] In summary, the safety protection module not only enhances the system's reliability under high-speed cutting and complex dynamic conditions, but also reduces the impact of equipment failures on the production process, improving operational safety and providing a solid guarantee for the application of the slicing machine in large-scale industrial production. Simultaneously, this module can work in conjunction with high-dynamic PID closed-loop control and feedforward compensation mechanisms to achieve dual protection of dynamic tension adjustment and fault protection, enabling the photovoltaic diamond wire slicing machine to maintain high efficiency and high-precision cutting while also possessing excellent safety and stability.

[0091] In this embodiment, the bearing of the guide wheel is a high-temperature resistant bearing.

[0092] The servo motor in the servo motor drive unit is a high dynamic response servo motor with a torque response time of less than 1ms and an overload capacity of more than 3 times the rated torque.

[0093] In this embodiment, the servo motor equipped in the servo motor drive unit is a high dynamic response servo motor with a torque response time of less than 1 millisecond and an overload capacity of more than 3 times the rated torque. A torque response time of less than 1 millisecond means that when the central controller or high dynamic PID control algorithm issues a speed or torque adjustment command, the servo motor can almost complete the torque output response within less than 1 millisecond, achieving instantaneous adjustment of the guide wheel's linear speed. An overload capacity of more than 3 times the rated torque means that the servo motor can withstand instantaneous tension far exceeding the rated load for a short period without damage or loss of synchronization. Taking a real-world example, suppose a slicing machine is cutting a 156mm × 156mm silicon ingot. When the surface hardness of the silicon ingot locally increases, causing a sudden increase in the stress on the diamond wire, the tension monitoring unit of the wire tension control guide wheel detects low tension and requires the guide wheel to immediately increase its linear speed for tension compensation. At this point, the high dynamic response servo motor can complete speed adjustment in less than 1 millisecond, quickly restoring the tension to the target value. Simultaneously, when instantaneous load peaks occur, the motor's overload capacity can withstand additional tension, preventing the guide wheel from losing synchronization or the diamond wire from breaking. By employing this high dynamic response servo motor, this system can achieve millisecond-level tension adjustment, significantly reducing the risk of diamond wire breakage caused by instantaneous force fluctuations, improving the thickness uniformity and surface flatness of the cutting disc, and enhancing the reliability and industrial application value of the entire active control guide wheel system under high-speed, high-load, and complex dynamic conditions.

[0094] The guide wheel is made of lightweight material; preferably carbon fiber composite material, to reduce rotational inertia and improve the accuracy of PID closed-loop control.

[0095] The guide wheel surface is coated with a friction-reducing and wear-resistant coating, preferably a composite coating containing polyurethane elastomer, molybdenum disulfide and aluminum oxide, to reduce the impact of frictional disturbances on PID tension control.

[0096] In this embodiment, the guide wheel is made of a lightweight material, preferably carbon fiber composite material. The guide wheel's light weight and low moment of inertia mean that when the central controller issues a speed adjustment command or the high-dynamic PID control algorithm calculates the target speed correction Δn, the guide wheel can respond more quickly, achieving precise adjustment of the linear speed. For example, when cutting a 156mm × 156mm silicon ingot, the diamond wire experiences instantaneous tension fluctuations due to localized hardness changes. The lightweight guide wheel can complete the speed adjustment within milliseconds, thereby quickly compensating for the tension and avoiding excessive instantaneous stretching or slack caused by tension lag. Compared to traditional steel or aluminum guide wheels, carbon fiber composite material guide wheels can significantly improve the accuracy of PID closed-loop control and the system's dynamic response capability.

[0097] Furthermore, the guide wheel surface is coated with a friction-reducing and wear-resistant coating, preferably a composite coating comprising polyurethane elastomer, molybdenum disulfide, and aluminum oxide. This coating has a low coefficient of friction, high wear resistance, and a certain degree of elasticity, which can effectively reduce frictional disturbances generated during the sliding of the diamond wire on the guide wheel surface. For example, during high-speed cutting, if there are frictional fluctuations at the contact surface between the diamond wire and the guide wheel, it will cause local tension fluctuations, thereby affecting the accuracy of PID closed-loop regulation. The guide wheel coated with the composite coating can smooth the movement of the diamond wire, reduce the interference of frictional changes on tension control, and enable the linear velocity correction ΔV(t) output by the PID control algorithm to be more accurately converted into actual guide wheel speed adjustment, thereby achieving fine control of tension throughout the entire path.

[0098] In summary, by employing lightweight carbon fiber composite guide wheels and a friction-reducing and wear-resistant composite coating, the active control guide wheel system of this application embodiment can achieve rapid response and precise tension adjustment under high-speed cutting and complex dynamic conditions, reduce the risk of diamond wire breakage, improve the uniformity of cutting blade thickness and surface flatness, and further improve silicon wafer yield and cutting efficiency, thus having significant industrial application value.

[0099] In this embodiment, the tension-speed sensitivity coefficient Kt is a key parameter used to convert the control action u(t) output by the PID control algorithm into the guide wheel linear speed correction ΔV(t). Its physical meaning lies in quantifying the response of the guide wheel linear speed adjustment to changes in diamond wire tension. In other words, the tension-speed sensitivity coefficient Kt characterizes the gain characteristic of a unit control action on the guide wheel speed, ensuring that the closed-loop control action can effectively compensate for tension deviations in the actual guide wheel-diamond wire system, thereby achieving high-precision tension adjustment. Specifically, the process of pre-setting the tension-speed sensitivity coefficient Kt includes the following steps:

[0100] First, a static tension-speed response test was conducted on the guide wheel-diamond wire system under no-cutting load or low-speed trial cutting conditions. By adjusting the guide wheel linear speed ΔV and collecting the tension change ΔT from the tension monitoring unit in real time, the static sensitivity relationship between the guide wheel speed change and the diamond wire tension change can be obtained. For example, at the wire inlet tension control guide wheel, the guide wheel linear speed was increased by 20 mm / s from 1200 mm / s, and the tension change from the tension monitoring unit was observed. For example, the tension increased from 10 N to 10.6 N, then the static sensitivity coefficient K... t，static It can be preliminarily calculated as follows:

[0101] K t，static =ΔV / ΔT=20 mm / s÷0.6 N≈33.3 mm / (s·N)

[0102] Due to the inertia, elasticity, and friction effects between the diamond wire and the guide wheel during actual cutting, the static sensitivity coefficient needs dynamic correction. By applying small-amplitude velocity disturbances to the guide wheel under different loads, accelerations, and frequency ranges, and recording the response curves of the tension monitoring unit, the dynamic gain G(s) of the diamond wire-guide wheel system is obtained using system identification methods (such as least squares fitting of a first- or second-order transfer function model). The dynamic sensitivity coefficient Kt can be approximately determined by the average value of the system gain over the operating frequency range, i.e.: Kt = ΔV 动态 / ΔT 动态 This step compensates for the phase delay of inertial hysteresis, friction fluctuations, and tension fluctuations, making the linear velocity correction of the PID output more accurately match the actual tension change. In the embodiments of this application, ΔT 动态 This represents the change in actual tension of the diamond wire under dynamic disturbance conditions, expressed in Newtons (N). Specifically, by applying a small velocity disturbance to the guide wheel, such as ±10 mm / s, the tension monitoring unit measures the instantaneous change in the diamond wire tension in real time, thus recording the actual tension fluctuation experienced by the diamond wire. For example, if the tension increases from 10 N to 10.5 N when the speed of the guide wheel suddenly increases by 10 mm / s, then ΔT... 动态 A value of 0.5N indicates the actual change in tension of the diamond wire at this point.

[0103] And ΔV 动态 This represents the velocity disturbance applied to the guide wheel in a dynamic experiment, measured in millimeters per second (mm / s). It is a change in linear velocity applied artificially or systematically to stimulate the system's dynamic response, thereby measuring the corresponding tension change. For example, if a velocity disturbance of +10 mm / s is applied to the guide wheel, then this 10 mm / s corresponds to ΔV. 动态 Used to compare with the measured ΔT 动态Together, we calculate the dynamic sensitivity coefficient Kt. The combination of these two parameters accurately reflects the tension-velocity relationship of the diamond wire-guide wheel system under dynamic conditions, providing a precise adjustment basis for high-dynamic PID control.

[0104] Because the guide rollers in the system are located in different positions (inlet side, cutting roller side, outlet side), the tension transmission characteristics of the diamond wire differ in each section, and the Kt value needs to be calibrated separately for each guide roller. For example, the inlet tension control guide roller, being close to the tension source, has a fast system response, and Kt can be set to approximately 30–35 mm / (s·N); while the outlet guide roller of the cutting roller is more affected by the cutting resistance of the silicon ingot, resulting in a slightly slower response, and Kt can be set to 28–32 mm / (s·N). In addition, for different diamond wire diameters, guide roller materials, and tension levels, Kt can be further optimized through experimental curve fitting or simulation modeling.

[0105] After initial setup, the tension compensation effect can be verified through actual cutting experiments. Monitor the deviation and fluctuation of the tension along the entire diamond wire path, and fine-tune Kt based on error statistics to ensure that ΔV(t) can quickly and smoothly adjust the guide wheel speed under typical cutting conditions, achieving stable tension throughout the entire path. If significant tension fluctuations are found in a particular guide wheel under specific transient loads, the Kt value for that guide wheel can be appropriately increased to enhance the speed correction range.

[0106] In summary, the tension-velocity sensitivity coefficient Kt is preset based on the system's static characteristics, dynamic response, the positional characteristics of each guide wheel, and actual cutting experiment data. By reasonably determining Kt, the linear velocity correction ΔV(t) output by the PID control algorithm can be physically precisely correlated with the diamond wire tension deviation ΔT, thereby achieving millisecond-level rapid response, synchronous tension adjustment throughout the entire path, improving the uniformity of the cut sheet thickness, surface flatness, and system stability, and enhancing the industrial application value of photovoltaic diamond wire slicing machines under high-speed, high-load, and complex dynamic conditions.

[0107] In this embodiment, the tension monitoring unit is a crucial sensing device for the active control guide wheel system. Its function is to acquire real-time tension data of the diamond wire at each guide wheel, providing accurate and timely input information for high-dynamic PID closed-loop control and feedforward compensation. The tension monitoring unit typically employs a high-precision non-contact or contact tension sensor, and its arrangement is tailored to the actual working conditions of the diamond wire-guide wheel system to ensure coverage of critical nodes in the cutting path, achieving full-path, multi-point tension monitoring. Specifically, the tension monitoring unit can employ the following typical detection methods at each guide wheel position:

[0108] For example, in the first method, a miniature force sensor is installed on the guide wheel bearing or support structure to directly measure the tangential tension borne by the guide wheel. For instance, at the wire tension control guide wheel, a high-sensitivity strain gauge force sensor is fixed to the guide wheel bracket. The tension of the diamond wire on the guide wheel surface is transmitted through the guide wheel bearing to the bracket, where the minute deformation is captured by the sensor, converted into an electrical signal, and transmitted to the central controller in real time.

[0109] In some embodiments, a finely adjustable tension measuring wheel can also be installed on the guide wheel bracket. The tension of the diamond wire can be reflected by measuring the minute changes in the rotation angle of the wheel. For example, during the cutting process, the tension of the diamond wire increases, causing the tension wheel to deflect by a small free rotation angle θ. By accurately measuring θ with an angle sensor and combining it with the known contact radius R between the diamond wire and the tension wheel, the tension value T=Kθ·θ can be calculated, where Kθ is the stiffness coefficient of the tension wheel.

[0110] Through the aforementioned multiple sensing methods, the tension monitoring unit can independently and in real-time collect the diamond wire tension value at each guide roller and generate a continuous tension curve. For example, when cutting a 156mm×156mm silicon ingot, the tension at the inlet tension control guide roller decreases from 10N to 9.4N in real time, while the tension at the outlet guide roller of the cutting roller increases from 10N to 11.1N. These data are fed back to the central controller by the tension monitoring unit at a millisecond-level sampling frequency for high-dynamic PID closed-loop and feedforward compensation calculations. In this embodiment, multi-point independent tension acquisition avoids the tension transmission lag problem caused by traditional single-point measurement, enabling tension monitoring throughout the cutting path. Secondly, the central controller can accurately calculate the target linear velocity correction ΔV(t) of each guide wheel using real-time data acquired by high-precision sensors, ensuring that the diamond wire remains under uniform and stable force throughout the cutting path. Thirdly, non-contact or low-friction sensing methods reduce additional disturbances to the diamond wire, ensuring the authenticity of tension data and improving the accuracy of PID closed-loop regulation. Finally, real-time tension acquisition provides a reliable basis for feedforward compensation, enabling the system to respond quickly under complex dynamic conditions such as spindle acceleration and deceleration, wire winding and unwinding acceleration disturbances, and local hardness changes in silicon ingots, thereby significantly reducing the risk of wire breakage and improving the uniformity of slice thickness, surface flatness, and silicon wafer yield.

[0111] In this embodiment, active control of the diamond wire tension is achieved by independently equipping each guide wheel with a servo motor and using a high-dynamic PID control algorithm to adjust the rotational speed of each guide wheel based on the real-time diamond wire tension data collected by the tension monitoring unit in conjunction with the central controller. This control method can compensate for the diamond wire tension deviation ΔT in real time, and ensure that the tension of the diamond wire remains within the preset target range during the cutting process by calculating the target rotational speed correction Δn and the real-time target linear velocity V, thereby effectively improving the slicing accuracy and cutting quality. Secondly, the safety protection module introduced in this embodiment includes a rotational speed detection unit, an anomaly judgment unit, and a protection execution unit. It can monitor the rotational speed of each guide wheel in real time, determine whether the rotational speed deviation of the guide wheel exceeds a preset threshold, and send an emergency braking command to the central controller in abnormal situations to achieve safe shutdown control of the servo motor drive unit, spindle motor, and take-up and unwinding motor. This measure effectively prevents diamond wire breakage or equipment damage caused by abnormal guide wheel rotational speed, improving the safety and reliability of system operation. Furthermore, the guide wheel of this application uses a high-temperature resistant bearing, which can adapt to the high-temperature environment that may be generated during the cutting process and ensure the long-term stable operation of the guide wheel; the high dynamic response servo motor has a torque response time of less than 1ms and a high overload capacity, which can quickly respond to tension changes and improve the accuracy and reliability of tension adjustment; the guide wheel is made of lightweight material and coated with a friction-reducing and wear-resistant coating, which effectively reduces friction loss and energy consumption, while reducing wear on the diamond wire, thereby extending the life of the diamond wire and the equipment.

[0112] On the other hand, embodiments of this application also provide an active control guide wheel method for a photovoltaic diamond wire slicing machine, the method being executed by the aforementioned active control guide wheel system for the photovoltaic diamond wire slicing machine.

[0113] The active control guide wheel method for a photovoltaic diamond wire slicing machine provided in this application embodiment enables real-time monitoring and precise control of diamond wire tension. By collecting diamond wire tension data at each guide wheel in real time, calculating the tension deviation ΔT, and inputting the deviation into a high-dynamic PID control algorithm, the target speed correction amount Δn for each guide wheel is obtained, thus forming a real-time target linear velocity V, which precisely adjusts the speed of each guide wheel servo motor. This method effectively compensates for tension fluctuations in the diamond wire during the cutting process, ensuring that the diamond wire tension remains within a preset target range, thereby improving cutting accuracy and quality. Furthermore, by combining feedforward compensation with PID closed-loop control, this method can adjust the linear velocity of each guide wheel in advance based on known disturbances (including acceleration information of the spindle motor and take-up / unwinding motor), improving the system's response speed and dynamic control capability. The method also includes safety protection measures. When the guide wheel speed deviation exceeds a preset threshold, emergency braking is triggered in a timely manner, and each motor stops operating according to the safe shutdown sequence, thereby ensuring operational safety and preventing damage to the equipment and diamond wire. Meanwhile, this method, combined with a high dynamic response servo motor, high-temperature resistant guide wheel bearings, and a lightweight, wear-resistant guide wheel design, enables stable operation in high-temperature, high-speed cutting environments, reducing energy consumption and diamond wire wear, and extending the service life of both the equipment and the diamond wire. The implementation of this method not only achieves stable and high-precision control of the cutting process but also improves production efficiency and system reliability, demonstrating significant technical and economic benefits.

[0114] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0115] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0116] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0117] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0118] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An active control guide wheel system for a photovoltaic diamond wire slicing machine, characterized in that, include: The left and right reels are used for loading and unloading diamond wire, respectively. Multiple guide rollers are disposed between the left wire roller and the right wire roller, and the multiple guide rollers include at least an inlet wire guide roller, an inlet tension control guide roller, a cutting roller inlet guide roller, a cutting roller outlet guide roller, an outlet tension control guide roller, and an outlet wire guide roller; The servo motor drive unit includes a servo motor independently equipped for each of the following guide wheels: the wire feeding guide wheel, the wire feeding tension control guide wheel, the cutting roller wire feeding guide wheel, the cutting roller wire output guide wheel, the wire output tension control guide wheel, and the wire output guide wheel. The tension monitoring unit is used to collect diamond wire tension data in real time and feed the tension data back to the central controller; The spindle motor drives the cutting spindle to rotate and provides spindle speed data to the central controller; The take-up and release motors drive the left and right reels respectively to realize the take-up and release of the diamond wire; The central controller is communicatively connected to the servo motor drive unit, the spindle motor, and the take-up and unwind motor. It is used to adjust the rotational speed of each guide roller based on the diamond wire tension data collected in real time by the tension monitoring unit, using a high-dynamic PID control algorithm.

2. The active control guide wheel system of the photovoltaic diamond wire slicing machine according to claim 1, characterized in that, The system further includes: a security protection module; the security protection module includes: The rotational speed detection unit is used to detect the rotational speed of each guide wheel in real time; An anomaly detection unit is used to compare the rotational speed of each guide wheel detected by the rotational speed detection unit with a preset rotational speed threshold, and to determine whether the rotational speed deviation of any guide wheel exceeds the preset threshold. The protection execution unit is used to send an emergency braking command to the central controller when the speed deviation of any guide wheel exceeds the preset threshold. The central controller is also used to control the servo motor drive unit, spindle motor and take-up / reel-out motor to stop rotating sequentially according to a preset safe stopping sequence after receiving the emergency braking command.

3. The active control guide wheel system of the photovoltaic diamond wire slicing machine according to claim 2, characterized in that, Based on the real-time diamond wire tension data collected by the tension monitoring unit, a high-dynamic PID control algorithm is used to adjust the rotational speed of each guide wheel, specifically including: Based on the real-time diamond wire tension data collected by the tension monitoring unit, the tension deviation value ΔT at each guide wheel is obtained. The tension deviation value ΔT is the difference between the actual measured diamond wire tension and the preset target tension. The tension deviation value ΔT is input into the high dynamic PID control algorithm to calculate the target speed correction amount Δn for each guide wheel. Based on the linear velocity signal V0 provided by the spindle motor, the target speed correction amount Δn is superimposed to form the real-time target linear velocity V = V0 + Δn for each guide wheel; The rotational speed output of the servo motor of each guide wheel in the servo motor drive unit is controlled so that the guide wheel on the servo motor achieves the real-time target linear velocity.

4. The active control guide wheel system of the photovoltaic diamond wire slicing machine according to claim 3, characterized in that, The tension deviation value ΔT is input into the high dynamic PID control algorithm to calculate the target speed correction amount Δn for each guide wheel, specifically including: The tension deviation value is used as the input to the closed-loop control, and the control action is calculated using a high-dynamic PID control algorithm; the PID control algorithm includes proportional, integral, and derivative actions. The proportional control function generates a control action that is proportional to the current tension deviation value. The integral function is to integrate the historical tension deviation; The differential action is used to predict the rate of change of tension deviation; The control input is converted into a target linear velocity correction for each guide wheel.

5. The active control guide wheel system of the photovoltaic diamond wire slicing machine according to claim 4, characterized in that, The control action quantity is converted into the target linear velocity correction quantity of each guide wheel by means of: converting the control action quantity into the target linear velocity correction quantity of each guide wheel through a conversion formula; The conversion formula is: ΔV(t) = Kt × u(t); Where ΔV(t) is the linear velocity correction of the guide wheel, Kt is the pre-set tension-velocity sensitivity coefficient, and u(t) is the control action.

6. The active control guide wheel system of the photovoltaic diamond wire slicing machine according to claim 5, characterized in that, The high dynamic PID control algorithm also includes feedforward compensation, which is used to adjust the linear speed of each guide wheel in advance according to known disturbances in the system. The disturbances include: acceleration information of the spindle motor and the take-up and unwind motor. The feedforward compensation and the PID closed-loop control output are superimposed to form the control action of each guide wheel.

7. The active control guide wheel system of the photovoltaic diamond wire slicing machine according to claim 1, characterized in that, The bearing of the guide wheel is a high-temperature resistant bearing.

8. The active control guide wheel system of the photovoltaic diamond wire slicing machine according to claim 1, characterized in that, The servo motor in the servo motor drive unit is a high dynamic response servo motor with a torque response time of less than 1ms and an overload capacity of more than 3 times the rated torque.

9. The active control guide wheel system of the photovoltaic diamond wire slicing machine according to claim 1, characterized in that, The guide wheel is made of lightweight material; The surface of the guide wheel is coated with a friction-reducing and wear-resistant coating.

10. A method for actively controlling the guide wheel of a photovoltaic diamond wire slicing machine, characterized in that, The method is performed by the active control guide wheel system of the photovoltaic diamond wire slicing machine according to any one of claims 1-9.

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