Servo drive braking circuit and servo drive control method

Abstract

The application provides a kind of servo drive brake circuit and servo driver control method, it is related to servo driver control technical field. Including main circuit and drive circuit, drive circuit is connected with main circuit and is used to drive and the brake of the servo driver connected with main circuit, still include main control chip and detection circuit, main circuit includes power MOS tube, freewheeling diode, state detection resistance and external brake resistance;The servo drive brake circuit of the application solves the problem that prior art fault judgment logic and hardware circuit are complex, realizes that judgment logic is simplified, can be quickly diagnosed to the main fault of brake circuit, and the diagnosis logic is clear and convenient for user to quickly locate fault, and the hardware design of detection circuit is simple, can effectively reduce implementation cost, is conducive to wide application.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of servo driver control, in particular to a servo drive braking circuit and a servo driver control method. BACKGROUND

[0002] During the operation of a servo motor, when encountering load changes, performing braking or deceleration operations, due to the inertia of the motor, energy will be fed back to the servo controller, causing the drive bus voltage to rise. If the bus voltage is too high, it may cause the internal devices of the controller to be damaged due to overvoltage, ultimately causing the controller to fail and affecting the stable operation of the entire system. In order to effectively deal with this problem, a braking circuit is specially provided in the servo drive controller to absorb this feedback energy, ensuring that the system bus voltage remains within a safe range, and making the operation of the motor more stable and reliable. Therefore, in the design of servo drive, the configuration of the braking circuit is particularly important, which needs to adapt to the load changes and braking requirements in various application scenarios to ensure the best performance of the system.

[0003] The prior art proposes to increase a dedicated fault diagnosis chip and corresponding control and feedback circuit to realize fault diagnosis of the braking circuit, thereby solving the problem that the possible faults of the braking circuit itself cannot be accurately judged. However, the prior art solves this problem based on a multi-signal combination judgment method, which has complex fault judgment logic and requires a relatively complex hardware circuit, resulting in relatively high cost, which limits its wide application to some extent. SUMMARY

[0004] The present application aims to provide a servo drive braking circuit and a servo driver control method, which solves the problem of complex fault judgment logic and hardware circuit of the prior art, simplifies the judgment logic, can quickly diagnose the main faults of the braking circuit, the diagnosis logic is clear and convenient for users to quickly locate faults, the hardware design of the detection circuit is simple, can effectively reduce the implementation cost, and is conducive to wide application.

[0005] In a first aspect, the present application provides a servo drive braking circuit, comprising a main loop and a drive circuit, the drive circuit being connected with the main loop and being used to drive a servo driver connected with the main loop to brake, further comprising a master control chip and a detection circuit, the main loop comprising a power MOS tube, a freewheeling diode, a state detection resistor and an external braking resistor.

[0006] The gate of the power MOS tube is connected with the driving circuit; one end of the source of the power MOS tube is connected with one end of the state detection resistor, and the other end of the state detection resistor is connected with the servo driver; the source of the power MOS tube is also connected with the detection circuit, and the drain of the power MOS tube is simultaneously connected with one end of the freewheeling diode and one end of the external braking resistor; the other end of the external braking resistor is simultaneously connected with the other end of the freewheeling diode and the servo driver; and the detection circuit can communicate with the driving circuit through the main control chip.

[0007] The servo drive braking circuit provided by the application can realize fault judgment of the braking circuit through a simpler circuit design and judgment logic, avoid further damage of related circuits caused by opening of the braking circuit when the braking circuit has a fault, and can timely find and locate the fault after the braking circuit runs.

[0008] Further, the resistance of the state detection resistor satisfies the following condition:

[0009] ;

[0010] Among them, is the resistance of the state detection resistor, is the bus voltage of the servo driver, is the loop current when the main loop works normally, is the resistance of the external braking resistor, and the is the on-resistance of the power MOS tube.

[0011] Further, the driving circuit comprises a driving chip, a first resistor, a second resistor and a first diode.

[0012] Among them, the driving chip is used for receiving the detection signal sent by the main control chip, the driving chip is simultaneously connected with the first end of the first resistor and the first end of the second resistor, the second end of the second resistor is connected with the negative electrode of the first diode, and the positive electrode of the first diode is connected with the second end of the first resistor and is used for outputting a driving signal.

[0013] Further, the detection circuit comprises a third resistor, an optical coupling chip and a fourth resistor.

[0014] The first end of the third resistor is used for receiving the electric signal sent by the state detection resistor, the second end of the third resistor is connected with the positive pole of the diode side of the optocoupler chip, and the negative pole of the diode side of the optocoupler chip is grounded; the collector of the triode side of the optocoupler chip is connected with the first end of the fourth resistor, the second end of the fourth resistor is used for outputting a power supply voltage, and the collector of the triode side of the optocoupler chip is also used for outputting a feedback signal to the master control chip; and the emitter of the triode side of the optocoupler chip is grounded.

[0015] Further, the conduction current of the diode side of the optocoupler chip satisfies the following condition:

[0016] ;

[0017] ;

[0018] ;

[0019] wherein, is the conduction current of the diode side of the optocoupler chip, is the voltage across the state detection resistor, is a preset conduction voltage, is the resistance of the third resistor, is the resistance of the state detection resistor, is a preset expected resistance power.

[0020] In a second aspect, the present application provides a servo driver control method based on the servo drive braking circuit, comprising the following steps:

[0021] S1. periodically sampling the bus voltage of the servo driver;

[0022] S2. comparing the bus voltage of the servo driver with a preset braking function opening threshold value, if the bus voltage of the servo driver is greater than or equal to the braking function opening threshold value, controlling the master control chip to send a first detection signal to make the detection circuit output a first feedback signal, and judging the state of the servo drive braking circuit according to the first feedback signal, and performing corresponding actions; the first detection signal is a pulse signal in which low-level pulse signals and high-level pulse signals alternately change according to unit pulse time;

[0023] S3. comparing the bus voltage of the servo driver with a preset brake function closing threshold value, if the bus voltage of the servo driver is less than the brake function closing threshold value, controlling the master control chip to send a second detection signal to make the detection circuit output a second feedback signal, and judging the state of the servo drive brake circuit according to the second feedback signal, and performing corresponding actions; the second detection signal is a pulse signal in which low-level pulse signals and high-level pulse signals alternately change in unit pulse time.

[0024] Compared with the prior art, the diagnosis method based on pulse mode analysis can judge whether a fault occurs and the specific fault type through a single signal, and the complexity of the judgment logic is simplified.

[0025] Further, the step S2 of judging the state of the servo drive brake circuit according to the first feedback signal and performing corresponding actions comprises:

[0026] S21. if the continuous three pulse times of the first feedback signal are all high-level pulse signals, it is judged that the servo drive brake circuit is in a first abnormal state, a fault warning is issued, and a first fault type is reported;

[0027] S22. if the continuous three pulse times of the first feedback signal are all low-level pulse signals, it is judged that the servo drive brake circuit is in a second abnormal state, a fault warning is issued, and a second fault type is reported;

[0028] S23. if the continuous three pulse times of the first feedback signal are low-level pulse signals and high-level pulse signals alternately changing pulse signals, it is judged that the servo drive brake circuit is in a normal state, and the brake function is started.

[0029] Further, the step S3 of judging the state of the servo drive brake circuit according to the second feedback signal and performing corresponding actions comprises:

[0030] S31. if the continuous three pulse times of the second feedback signal are all high-level pulse signals, it is judged that the servo drive brake circuit is in a third abnormal state, a fault warning is issued, and a third fault type is reported;

[0031] S32. if the continuous three pulse times of the second feedback signal are all low-level pulse signals, it is judged that the servo drive brake circuit is in a fourth abnormal state, a fault warning is issued, and a fourth fault type is reported;

[0032] S33. if the continuous three pulse times of the second feedback signal are low-level pulse signals and high-level pulse signals alternately changing pulse signals, it is judged that the servo drive brake circuit is in a normal state, and the step S1 is returned to be executed.

[0033] Further, the first fault type and the third fault type are both open circuit of the external braking resistor or power MOS tube in the servo drive braking circuit.

[0034] Further, the second fault type and the fourth fault type are both short circuit of the power MOS tube in the servo drive braking circuit.

[0035] From the above, the servo drive braking circuit provided by the present application simplifies the hardware design of the detection circuit compared with the prior art, can effectively reduce the implementation cost, is conducive to wide application, and simultaneously no longer needs to adopt the multi-channel signal combination judgment mode to judge the fault of the braking circuit, the corresponding judgment logic is correspondingly simplified, the main fault of the braking circuit can be quickly diagnosed, the diagnosis logic is clear and convenient for the user to quickly locate the fault.

[0036] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art upon examination of the following or can be learned by practice of the present application. The objects and other advantages of the present application can be achieved and attained by the structures particularly pointed out in the written description and claims hereof as well as the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 A structural schematic diagram of a servo drive braking circuit provided by an embodiment of the present application.

[0038] Figure 2 A structural schematic diagram of a drive circuit in an embodiment of the present application.

[0039] Figure 3 A structural schematic diagram of a detection circuit in an embodiment of the present application.

[0040] Figure 4 A flow chart of a servo drive control method provided by an embodiment of the present application.

[0041] Figure 5 A waveform signal schematic diagram of detection signals and feedback signals of the servo drive braking circuit in different states in an embodiment of the present application.

[0042] LABEL EXPLANATION:

[0043] 100, main circuit; 200, driving circuit; 210, driving chip; 300, master chip; 400, detection circuit; Q, power MOS tube; Dx, freewheeling diode; Ra, state detection resistor; Rb, external brake resistor; R1, first resistor; R2, second resistor; D1, first diode; Qg, detection signal; Qgb, driving signal; R3, third resistor; OP, optical coupling chip; R4, fourth resistor; Vcc, power supply voltage; Bfb, feedback signal; M, servo motor. DETAILED DESCRIPTION

[0044] Embodiments of the present application are described below in detail with reference to the accompanying drawings, wherein the same or similar components or components having the same or similar functions are denoted by the same or similar reference numerals throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and cannot be understood as a limitation of the present application.

[0045] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0046] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0047] In the present application, unless specifically defined and limited otherwise, the "on" or "under" of a first feature to a second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "on", "above" and "under" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The "under", "below" and "under" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.

[0048] The following disclosure provides many different embodiments, or examples, for implementing different structures of the present application. For the purpose of simplification, the elements of the particular examples in the following description are described and illustrated in the context of specific examples. Of course, they are by way of example only and are not intended to be limiting of the application. Further, the present application can refer to a number of elements by reference to a drawing in which the drawing figure number is identified following first identification of an element in the description. Such references are used for the purpose of simplification and clarity and are not intended to indicate or create a relationship between the various embodiments and / or features discussed in the description. Additionally, the present application provides examples of various specific processes and materials, but one of ordinary skill in the art can recognize that other processes can be used and / or other materials can be employed.

[0049] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0050] It should be noted that similar reference numbers and letters refer to similar items in the following drawings, and therefore, once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings. In addition, the terms "first", "second" are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless specifically defined and limited otherwise. At the same time, in the description of the present application, the terms "first", "second" and the like are only used for differentiation, and cannot be understood as indicating or implying relative importance.

[0051] Reference to the accompanying drawings Figure 1 The application provides a servo drive braking circuit, which comprises a main circuit 100 and a drive circuit 200 connected with the main circuit 100 and used for driving a servo driver connected with the main circuit 100, and further comprises a master control chip 300 and a detection circuit 400, wherein the main circuit comprises a power MOS tube Q, a freewheeling diode Dx, a state detection resistor Ra and an external braking resistor Rb.

[0052] The gate of the power MOS tube Q is connected with the drive circuit 200; one end of the source of the power MOS tube Q is connected with one end of the state detection resistor Ra, and the other end of the state detection resistor Ra is connected with the servo driver; the source of the power MOS tube Q is further connected with the detection circuit 400, and the drain of the power MOS tube Q is simultaneously connected with one end of the freewheeling diode Dx and one end of the external braking resistor Rb, and the other end of the external braking resistor Rb is simultaneously connected with the negative electrode of the freewheeling diode Dx and the servo driver; the detection circuit 400 can communicate with the drive circuit 200 through the master control chip 300.

[0053] The state detection resistor refers to a resistor element used for sensing the state of the circuit, which can be realized in the form of a sampling resistor, a shunt, etc., and is mainly used for generating a detectable voltage signal when the braking current flows. The detection circuit refers to a circuit used for processing the signal generated by the state detection resistor and transmitting the state information to the master control chip, which can be realized in the form of an operational amplifier circuit, a comparator circuit, an analog-to-digital converter interface circuit or an optical coupling isolation circuit, etc., and is mainly used for converting an analog signal into a digital signal or an isolated signal for processing by the master control chip. The master control chip refers to a processor used for receiving the state information of the detection circuit, making logical judgments and controlling the drive circuit, which can be realized in the form of a microcontroller, a digital signal processor or a field programmable gate array, etc., and is mainly used for realizing intelligent control, state monitoring and fault diagnosis of the braking function. The drive circuit refers to a circuit used for receiving the electrical signal of the master control chip and generating a signal for driving the power MOS tube to be turned on or turned off, which can be realized in the form of a dedicated MOSFET drive chip, a discrete component drive circuit, etc., and is mainly used for providing sufficient voltage and current to quickly and effectively control the switching state of the power MOS tube.

[0054] The core innovation of the application lies in that the state detection resistor is introduced into the main circuit, and the detection circuit and the master control chip are combined, so that the working state of the braking circuit is directly or indirectly detected, thereby simplifying the complex fault judgment logic and hardware circuit in the prior art, reducing the cost, and improving the efficiency and accuracy of fault diagnosis.

[0055] Specifically, the servo drive braking circuit absorbs the energy fed back by the servo driver through the main loop, and controls the switching state of the main loop through the drive circuit. In specific work, when the bus voltage of the servo driver reaches the preset threshold, the main control chip controls the drive circuit to generate a drive signal according to the bus voltage state and internal logic, so that the power MOS tube in the main loop is turned on. At this time, the feedback energy is converted into heat energy consumption through the power MOS tube, the state detection resistor and the external braking resistor. The current flowing through the power MOS tube also flows through the state detection resistor, generating a voltage signal across the state detection resistor. The voltage signal is sent to the detection circuit for processing. The detection circuit feeds back the processed state information (for example, information reflecting whether the current exists or the size) to the main control chip. After receiving the state information fed back by the detection circuit, the main control chip analyzes and judges the current working state of the braking circuit (for example, whether it is normally turned on, whether it is open circuit or short circuit) in combination with the detection signal Qg sent to the drive circuit. According to the judgment result, the main control chip can continue to maintain the braking, close the braking, adjust the drive signal or issue a fault warning. The freewheeling diode provides a current path when the power MOS tube is turned off, protecting the power MOS tube. Through the state detection resistor and the detection circuit, the main control chip can obtain the running information of the braking loop in real time, so as to realize effective monitoring and fault diagnosis of the braking circuit.

[0056] As a preferred embodiment, the scheme of the application is implemented as follows: the main control chip can adopt a microcontroller of STM32 series. The drive circuit can adopt a dedicated MOSFET drive chip, such as IR2110. The state detection resistor can be a low resistance power resistor, such as a 0.1 ohm / 5 watt resistor. The detection circuit can adopt an optocoupler chip, such as PC817, whose diode side is connected to one end of the state detection resistor through a current limiting resistor, and whose collector is connected to a GPIO pin of the main control chip, and whose emitter is grounded. The power MOS tube can be a N-channel power MOSFET with appropriate voltage and current levels, such as IRF460. The external braking resistor can be a high-power wire-wound resistor, whose resistance value is determined according to system requirements. The freewheeling diode can be a fast recovery diode, such as FR307. The state detection resistor is connected in series between the source of the power MOS tube and the bus of the servo driver. The drain of the power MOS tube is connected to one end of the external braking resistor and the anode of the freewheeling diode. The other end of the external braking resistor is connected to the cathode of the freewheeling diode and the bus of the servo driver. The optocoupler diode of the detection circuit is connected across the state detection resistor (through the current limiting resistor), and the output of the optocoupler triode is connected to the input pin of the main control chip. The PWM output pin of the main control chip is connected to the input end of the drive chip, and the output end of the drive chip is connected to the gate of the power MOS tube.

[0057] By the above scheme, the application can effectively solve the problems of complex brake circuit fault judgment logic, complex hardware circuit and high cost in the prior art. By introducing a state detection resistor and cooperating with a detection circuit and a master control chip, real-time and simplified detection of the working state of the brake circuit is realized, the fault judgment logic is more direct, the required hardware circuit is simplified, thereby reducing the overall cost. At the same time, the detection capability of the brake circuit state change is beneficial to timely discover abnormal conditions, ensure that the brake circuit can work reliably in a normal state, effectively absorb feedback energy, and protect the servo driver.

[0058] In some embodiments, the resistance of the state detection resistor satisfies the following condition:

[0059] ;

[0060] wherein, Rais the resistance of the state detection resistor Ra, Vbusis the bus voltage of the servo driver, Iais the loop current when the main circuit 100 works normally, Rbis the resistance of the external brake resistor Rb, Ronis the on-resistance of the power MOS tube Q.

[0061] In some embodiments, reference is made to the accompanying drawings Figure 2 The driving circuit 200 includes a driving chip 210, a first resistor R1, a second resistor R2 and a first diode D1.

[0062] The driving chip 210 is configured to receive a detection signal Qg sent by the master control chip 300, and the driving chip 210 is connected with a first end of the first resistor R1 and a first end of the second resistor R2, a second end of the second resistor R2 is connected with a negative electrode of the first diode D1, a positive electrode of the first diode D1 is connected with a second end of the first resistor R1 and is configured to output a driving signal Qgb.

[0063] The driving chip is a kind of integrated circuit specially designed for driving power switch devices (such as power MOS tubes, IGBTs, etc.), which can be realized by using a dedicated gate drive chip. The first resistor R1 and the second resistor R2 are standard resistor elements for limiting current or adjusting voltage, which can be realized by using a surface mount resistor or a straight plug resistor. The first diode D1 is a semiconductor device with unidirectional conduction characteristics, which can be realized by using an ordinary rectifier diode or a fast recovery diode. The detection signal Qg is an electrical signal sent by the master chip for controlling the operation of the driving circuit, which can be realized by using a pulse width modulation (PWM) signal or a digital logic signal. The driving signal Qgb is an electrical signal output by the driving circuit and directly applied to the gate of the power MOS tube, whose waveform and level are suitable for driving the power MOS tube to switch operation.

[0064] Specifically, the driving circuit receives the detection signal Qg from the master chip through the driving chip. The output end of the driving chip is connected to one end of the first resistor R1 and the second resistor R2. The other end of the first resistor R1 is connected to the positive electrode of the first diode D1. The other end of the second resistor R2 is connected to the negative electrode of the first diode D1. The driving signal Qgb is output from the connection point of the other end of the first resistor R1 and the positive electrode of the first diode D1, and the output signal is applied to the gate of the power MOS tube. This connection forms an asymmetric driving path. When the driving chip outputs a high level (or an on signal), the current mainly charges the gate of the power MOS tube through the first resistor R1, making it conductive. When the driving chip outputs a low level (or an off signal), the charge of the gate of the power MOS tube is discharged through the path composed of the second resistor R2 and the first diode D1, making it off. By selecting different resistance values of the first resistor R1 and the second resistor R2, the turn-on and turn-off speeds of the power MOS tube can be independently controlled. For example, reducing the first resistor R1 can speed up the turn-on speed, and reducing the second resistor R2 can speed up the turn-off speed. The first diode D1 ensures that the current does not pass through the second resistor R2 during turn-on, and the current passes through the path of the second resistor R2 and the first diode D1 during turn-off. This asymmetric driving helps to optimize the switching waveform, reduce switching loss, and prevent the power MOS tube from mis-conducting during rapid voltage changes. The driving circuit converts the control command of the master chip into the voltage and current signals required for reliable driving of the power MOS tube, ensuring that the power MOS tube accurately switches according to the command. The reliable switching of the power MOS tube is the key to the normal operation of the braking circuit, which directly affects the absorption of braking energy and the accuracy of state judgment through the state detection resistor. Therefore, the reliability of the driving circuit directly supports the function implementation of the entire braking circuit and the effectiveness of the state detection mechanism.

[0065] Through the above scheme, the application provides a specific drive circuit structure, which can effectively receive the electrical signal of the master control chip and generate a reliable drive signal suitable for driving the power MOS tube. The circuit optimizes the switching characteristics of the power MOS tube through the design of asymmetric opening and closing paths, reduces the switching loss, and improves the driving efficiency and reliability. Thus, the accurate switching of the power MOS tube is ensured, so that the braking circuit can work normally according to the instructions of the master control chip, effectively absorb the feedback energy, maintain the stability of the bus voltage, and provide a basis for accurate detection of the state of the braking circuit through the state detection resistor.

[0066] In some embodiments, reference is made to the accompanying drawings Figure 3 The detection circuit 400 includes a third resistor R3, an optical coupling chip OP, and a fourth resistor R4.

[0067] The first end of the third resistor R3 is used to receive the electrical signal sent by the state detection resistor Ra, the second end of the third resistor R3 is connected to the positive electrode of the diode side of the optical coupling chip OP, and the negative electrode of the diode side of the optical coupling chip OP is grounded. The collector of the triode side of the optical coupling chip OP is connected to the first end of the fourth resistor R4, the second end of the fourth resistor R4 is used to output the supply voltage Vcc, and the collector of the triode side of the optical coupling chip OP is also used to output the feedback signal Bfb to the master control chip 300. The emitter of the triode side of the optical coupling chip OP is grounded.

[0068] The optical coupling chip refers to an electronic component that uses light as a medium to transmit electrical signals, thereby realizing electrical isolation between the input circuit and the output circuit. It usually contains a light-emitting element (such as a light-emitting diode) and a photosensitive element (such as a phototransistor or a photodarlington tube). This isolation feature can effectively block the influence of high voltage or noise on the input side on the low voltage circuit on the output side. The optical coupling chip can be implemented in multiple types, such as optical coupling with phototransistor output, photodarlington tube output, or logic gate output.

[0069] Specifically, the detection circuit builds a path containing an optocoupler chip, aiming to safely and reliably transmit the state signal on the state detection resistor in the main circuit to the master control chip. The first end of the third resistor is connected to the state detection resistor, receiving an electrical signal reflecting the state of the brake circuit. The second end of the third resistor is connected to the positive anode of the diode side of the optocoupler chip, and the negative anode of the diode side of the optocoupler chip is grounded, forming the input loop of the optocoupler chip. The third resistor limits the current flowing through the optocoupler diode. The core of the optocoupler chip lies in its optical isolation property between the input side (diode) and the output side (triode). When the current at the input side reaches a certain value, the diode emits light, and the optical signal triggers the triode at the output side to conduct. This isolation mechanism effectively isolates the state signal from the high-voltage side of the main circuit from the master control chip, improving the safety and anti-interference ability of the system. The collector of the triode side of the optocoupler chip is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the supply voltage, forming the output loop of the optocoupler chip. The fourth resistor acts as a pull-up resistor, pulling the collector voltage to the supply voltage when the optocoupler triode is off. When the optocoupler triode is on, the collector voltage drops. The optocoupler chip converts the optical signal received at the input side into an electrical signal (voltage change) at the output side, which is the feedback signal. This feedback signal is output from the collector of the triode side of the optocoupler chip and sent to the master control chip. Thus, according to the level change of the feedback signal received by the master control chip, the original electrical signal state on the state detection resistor is determined, and the current working state of the brake circuit is identified. This method uses the isolation and conversion function of the optocoupler chip to solve the problem of safe and reliable transmission of high-voltage state signals to the master control chip, providing a basis for subsequent state judgment and fault diagnosis.

[0070] Through the above scheme, the detection circuit provides a safe and reliable signal transmission path, effectively transmitting the state detection signal from the high-voltage side of the main circuit to the master control chip. It eliminates the safety hazards caused by high voltage through optical isolation, reduces signal interference, and solves the problem of level mismatch. This enables the control circuit to accurately obtain the state information of the brake circuit, thereby achieving effective state monitoring and fault diagnosis.

[0071] In some embodiments, the conduction current of the diode side of the optocoupler chip OP satisfies the following condition:

[0072] ;

[0073] wherein, is the conduction current of the diode side of the optocoupler chip OP, is the voltage across the state detection resistor Ra, is the preset conduction voltage, is the resistance of the third resistor R3.

[0074] It should be noted that, , ,therefore Because the state detection resistor Ra is in the system, when selecting the state detection resistor Ra, the voltage across the two ends of the state detection resistor Ra must be considered. The optocoupler chip in the subsequent detection circuit has the ability to drive. Secondly, the power of the state detection resistor Ra must be considered. The size of the state detection resistor Ra cannot be too large, so the power is generally set to be less than or equal to the expected resistance power (for example ). Therefore, in practical applications, the voltage across the state detection resistor Ra The following two conditions are met:

[0075] ;

[0076] .

[0077] in, is the resistance of the state detection resistor Ra, is the preset expected resistance power.

[0078] Reference Attachment Figure 4 The present invention provides a servo drive control method based on the servo drive brake circuit in the above embodiment, comprising the following steps:

[0079] S1. Periodically sample the bus voltage of the servo drive;

[0080] S2. Compare the bus voltage of the servo driver with a preset brake function activation threshold. If the bus voltage of the servo driver is greater than or equal to the brake function activation threshold, control the main control chip to send a first detection signal to cause the detection circuit to output a first feedback signal, and determine the state of the servo drive brake circuit based on the first feedback signal and perform a corresponding action; the first detection signal is a pulse signal in which a low-level pulse signal and a high-level pulse signal alternate according to a unit pulse time;

[0081] S3. Compare the bus voltage of the servo driver with the preset braking function shutdown threshold. If the bus voltage of the servo driver is less than the braking function shutdown threshold, control the main control chip to send a second detection signal to enable the detection circuit to output a second feedback signal, and judge the state of the servo drive braking circuit according to the second feedback signal, and perform corresponding actions; the second detection signal is a pulse signal in which a low-level pulse signal and a high-level pulse signal alternate according to a unit pulse time.

[0082] The master control chip refers to a central processing unit for executing control logic, generating electrical signals and processing feedback information, which can be implemented by a microcontroller, a digital signal processor or an application-specific integrated circuit. The detection circuit refers to a circuit for receiving the electrical signal generated by the state detection resistor in the braking circuit and converting it into a feedback signal readable by the master control chip, which can be implemented by a circuit structure containing elements such as resistors and optocoupler chips. The first detection signal and the second detection signal (both of which belong to the detection signal Qg) refer to a specific pulse sequence generated by the master control chip, which is used to actively detect the response characteristics of the braking circuit when attempting to drive. The specific pulse pattern of this signal is the basis for state diagnosis. The first feedback signal and the second feedback signal (both of which belong to the feedback signal Bfb) refer to the electrical signal output by the detection circuit according to the response of the braking circuit to the detection signal. The pattern of this signal reflects the current working state of the braking circuit. Determining the state of the servo drive braking circuit according to the first feedback signal and determining the state of the servo drive braking circuit according to the second feedback signal refer to determining whether the braking circuit is in a normal working state or in some abnormal state (such as open circuit or short circuit) by analyzing the pulse pattern of the received feedback signal (e.g., whether it is consistent with the sent detection signal pattern, or whether it exhibits a continuous high or low level). Performing corresponding actions refers to taking appropriate control measures (e.g., allowing or prohibiting the braking function to be turned on / off) or fault handling measures (e.g., issuing a warning signal) according to the determined state of the braking circuit.

[0083] Specifically, the method first periodically samples the bus voltage of the servo driver, which is the basis for brake control, because the high and low of the bus voltage directly reflects the degree of servo motor M feedback energy in the servo driver and whether the brake function needs to be started or turned off. Then, the sampled bus voltage is compared with the preset brake function opening threshold. When the bus voltage reaches or exceeds the opening threshold, it indicates that the servo driver bus voltage is too high, and the brake function needs to be started to consume the feedback energy. At this time, the control master chip sends a specific first detection signal, which is composed of low-level pulses and high-level pulses alternating according to unit pulse time. This pulse signal acts on the power MOS tube in the brake circuit through the driving circuit, making it try to switch according to the pulse mode. At the same time, the state detection resistor in the brake circuit will generate an electrical signal reflecting the current state of the circuit, which is received and processed by the detection circuit and outputs a first feedback signal. This way of sending a specific pulse signal and observing the circuit response (feedback signal) can detect the working state of the brake circuit. Then, according to the pulse mode of the received first feedback signal, the current state of the servo drive brake circuit is judged. If the feedback signal mode is consistent with the detection signal mode (i.e. also alternating pulses), it is judged that the circuit is in a normal state, and the brake function can be safely turned on. If the feedback signal mode is abnormal (for example, continuous high or low), it is judged that the circuit is in some abnormal state (such as open circuit fault), and a fault warning is issued to report the corresponding fault type, so as to avoid forced operation when the circuit is abnormal. Similarly, the sampled bus voltage is compared with the preset brake function closing threshold. When the bus voltage is lower than the closing threshold, it indicates that the bus voltage has dropped to a safe range and the brake function is no longer needed. At this time, the control master chip sends a second detection signal, which is also a pulse signal with low-level pulses and high-level pulses alternating according to unit pulse time. The detection circuit outputs a second feedback signal. According to the pulse mode of the received second feedback signal, the current state of the servo drive brake circuit is judged. If the feedback signal mode is normal (alternating), it is judged that the circuit is in a normal state, and the brake function can be safely turned off and returned to continue periodically sampling the bus voltage. If the feedback signal mode is abnormal (for example, continuous high or low), it is judged that the circuit is in some abnormal state (such as short circuit fault), and a fault warning is issued to report the corresponding fault type. This method uses the state detection resistor added in the brake circuit and the state information provided by the detection circuit to actively detect the circuit state by generating a specific pulse signal by the master control chip, and judges according to the feedback signal mode output by the detection circuit. This pulse mode-based diagnostic method enables the master control chip to effectively utilize hardware-based intelligent control and fault diagnosis, and converts the state detection capability of the hardware into executable control and processing logic.The method can effectively determine the normal working state and various abnormal states such as open circuit and short circuit of the brake circuit by performing state detection based on specific pulse signal and feedback signal mode analysis before starting and stopping the brake function, and take corresponding control or fault handling measures according to the determination result.

[0084] As a preferred embodiment, the scheme of the application is implemented as follows: the master control chip can adopt a microcontroller of STM32 series. The periodic sampling of the bus voltage can be realized by the ADC module of the microcontroller. The preset brake function starting threshold and stopping threshold are stored in the program memory of the microcontroller. When the bus voltage exceeds the starting threshold, the microcontroller generates a first detection signal through its GPIO pin or timer module, which is a pulse train alternating between low and high levels according to a preset unit pulse time (for example, 10 microseconds), and sends it to the drive circuit. The detection circuit can adopt a structure containing an optocoupler chip (for example, PC817) and a resistor, and the voltage change on the state detection resistor drives the LED of the optocoupler, and the triode side output of the optocoupler outputs a feedback signal. The microcontroller reads the first feedback signal output by the detection circuit through another GPIO pin. The firmware program of the microcontroller analyzes the pulse pattern of the received first feedback signal. For example, the program can check the signal level in the next three pulse times. If the feedback signal also presents an alternating pattern of high, low, high in these three pulse times, it is judged that the brake circuit is normal, and the microcontroller then outputs a continuous drive signal to start the brake function. If the feedback signal is continuously high or continuously low in these three pulse times, it is judged that the circuit is abnormal (for example, open circuit or short circuit), and the microcontroller does not start the brake function, but sends a fault warning message through a communication interface (such as CAN, RS485), and may light up a fault indicator light. Similarly, when the bus voltage is lower than the stopping threshold, the microcontroller generates a second detection signal, sends it to the drive circuit, and reads the second feedback signal output by the detection circuit. According to the pulse pattern of the second feedback signal, the state of the circuit is determined. If the feedback signal alternates normally, it is judged that the circuit is normal, the microcontroller stops outputting the drive signal to stop the brake function, and continues to sample the bus voltage. If the feedback signal is abnormal, it is judged that the circuit is abnormal, and a fault warning message is sent.

[0085] Through the above scheme, the application can accurately determine the state of the brake circuit (including normal working and various abnormal states), and execute corresponding control or fault handling according to the state, thereby improving the reliability and safety of the servo drive system. Moreover, this diagnosis method based on pulse pattern analysis can determine whether a fault occurs and the specific fault type through a single signal, which simplifies the complexity of the judgment logic compared with the prior art.

[0086] In some embodiments, reference is made to the accompanying drawings that form a part of this disclosure and in which are shown, by way of example, various embodiments of the application. Figure 5, in step S2, the state of the servo drive braking circuit is determined according to the first feedback signal, and the step of performing corresponding actions includes:

[0087] S21. If the first feedback signal is a high-level pulse signal in the continuous three pulse times, it is determined that the servo drive braking circuit is in a first abnormal state, a fault warning is issued, and a first fault type is reported;

[0088] S22. If the first feedback signal is a low-level pulse signal in the continuous three pulse times, it is determined that the servo drive braking circuit is in a second abnormal state, a fault warning is issued, and a second fault type is reported;

[0089] S23. If the first feedback signal is a pulse signal with low-level pulse signal and high-level pulse signal alternating in the continuous three pulse times, it is determined that the servo drive braking circuit is in a normal state, and the braking function is turned on.

[0090] Further, the first fault type is that the external braking resistor or power MOS tube in the servo drive braking circuit is open.

[0091] Further, the second fault type is that the power MOS tube in the servo drive braking circuit is short-circuited.

[0092] Wherein, the three pulse times refer to the continuous three specific time periods for observing or sampling the first feedback signal, and each time period corresponds to a unit pulse time of the first detection signal. The high-level pulse signal refers to the voltage of the signal within a specific pulse time being in a preset high-level range. The low-level pulse signal refers to the voltage of the signal within a specific pulse time being in a preset low-level range. The alternating pulse signal refers to the level of the signal being switched between high and low according to a certain order (such as low-high-low or high-low-high) in the continuous three pulse times. The first abnormal state and the second abnormal state refer to the abnormal working state of the servo drive braking circuit diagnosed according to the specific pulse mode of the first feedback signal, which represents different types of circuit faults or abnormal conditions. The normal state refers to the expected working state of the servo drive braking circuit diagnosed according to the specific pulse mode of the first feedback signal, indicating that the circuit can respond correctly to the detection signal. The fault warning refers to the system prompting the external existence of abnormal conditions through some way (such as indicator light, display screen, communication interface). The first fault type and the second fault type are reported, which means that the system further provides specific information about the detected abnormalities to facilitate fault location and elimination. The braking function is turned on, which means that the system activates the servo drive braking circuit to start absorbing feedback energy.

[0093] Specifically, when the bus voltage of the servo driver rises and reaches the brake function opening threshold, the master control chip starts a diagnostic process. The master control chip sends a first detection signal with a specific alternating pattern (e.g., low-high-low) to the drive circuit. This detection signal acts on the key components of the brake circuit (e.g., power MOS tube) through the drive circuit, and the state change of the brake circuit is monitored by the detection circuit to generate a first feedback signal. The core of this scheme is to analyze the level pattern of this first feedback signal within the continuous three pulse times. If the first feedback signal always remains high level within the three pulse times, the system determines that the brake circuit is in the first abnormal state, and triggers the corresponding fault warning and first fault type report. If the first feedback signal always remains low level within the three pulse times, the system determines that the brake circuit is in the second abnormal state, and triggers the fault warning and the second fault type report. Only when the first feedback signal presents the expected alternating pattern of low level and high level corresponding to the first detection signal (e.g., high-low-high) within the three pulse times, the system determines that the brake circuit is in the normal state, and further performs the operation of opening the brake function. This judgment mechanism based on the pulse pattern of the feedback signal utilizes the different response characteristics of the brake circuit in different states to the specific detection signal, providing a simple and effective diagnostic method. By combining with the structure of the servo drive brake circuit (including the state detection resistor and the detection circuit) and the specific detection signal sent by the master control chip, this scheme can accurately distinguish the normal and abnormal states of the brake circuit and take targeted measures, thereby improving the reliability of the brake function.

[0094] Specifically, the specific cause analysis of the first abnormal state is as follows:

[0095] When the external brake resistor Rb is open (i.e., the external brake resistor Rb is not connected), when the master control chip sends the detection signal Qg as low level, the light emitting diode of the optocoupler chip OP in the detection circuit is not conductive, and the corresponding triode is cut off, the feedback signal Bfb is pulled up to high level. When the master control chip sends the detection signal Qg as high level, the light emitting diode of the optocoupler chip OP in the detection circuit is not conductive, and the corresponding triode is cut off, the feedback signal Bfb is pulled up to high level.

[0096] When the power MOS tube Q is open, when the master control chip sends the detection signal Qg as low level, the light emitting diode of the optocoupler chip OP in the detection circuit is not conductive, and the corresponding triode is cut off, the feedback signal Bfb is pulled up to high level. When the master control chip sends the detection signal Qg as high level, the light emitting diode of the optocoupler chip OP in the detection circuit is not conductive, and the corresponding triode is cut off, the feedback signal Bfb is pulled up to high level.

[0097] Therefore, when the external braking resistor Rb or the power MOS tube Q in the braking circuit is open and when the main control chip sends a detection signal, the received feedback signal Bfb is three high-level pulse signals with a time of t.

[0098] Analysis of the specific causes of the second abnormal state:

[0099] When the power MOS tube Q is short-circuited and the detection signal Qg sent by the main control chip is low, the light-emitting diode of the optocoupler chip OP in the detection circuit is turned on, the corresponding transistor is turned on, and the feedback signal Bfb is pulled down to a low level. When the detection signal Qg sent by the main control chip is high, the light-emitting diode of the optocoupler chip OP in the detection circuit is turned on, the corresponding transistor is turned on, and the feedback signal Bfb is pulled down to a low level.

[0100] Therefore, when the power MOS tube Q in the brake circuit is short-circuited and when the main control chip sends a detection signal, the received feedback signal Bfb is three low-level pulse signals with a time of t.

[0101] Analysis of specific causes of normal status:

[0102] For example, the detection signal Qg is three pulse signals with a time t, which are low level, high level and low level respectively.

[0103] When the detection signal Qg is at a low level, the power MOS tube Q is turned off, the light-emitting diode of the optocoupler chip OP in the detection circuit is not turned on, the corresponding transistor is cut off, and the feedback signal Bfb is pulled up to a high level.

[0104] When the detection signal Qg is high, the power MOS tube Q is turned on, the light-emitting diode of the optocoupler chip OP in the detection circuit is turned on, and the corresponding transistor is turned on, and the feedback signal Bfb is pulled down to a low level. Therefore, under normal conditions, when the main control chip sends the detection signal Qg, the received feedback signal Bfb is three pulse signals with a time t, which are high, low, and high respectively.

[0105] Through the above scheme, this application provides a clear and operational logic for parsing the status information contained in the first feedback signal. It uses the pulse pattern of the feedback signal within a specific time window as a diagnostic basis, effectively classifying the circuit status into normal and different types of abnormalities, and associates clear response actions (fault warning / reporting or braking). This solves the problem of accurately determining the status of the servo drive brake circuit and executing the corresponding action based on the first feedback signal output by the detection circuit when the servo drive bus voltage reaches the brake activation threshold, thereby improving the reliability and fault diagnosis capabilities of the servo drive brake circuit.

[0106] In certain embodiments, reference is made to the accompanying Figure 5, the step S3 of judging the state of the servo drive braking circuit according to the second feedback signal and performing corresponding actions comprises:

[0107] S31. If the second feedback signal is a high-level pulse signal in the continuous three pulse times, it is judged that the servo drive braking circuit is in a third abnormal state, a fault warning is issued and a third fault type is reported;

[0108] S32. If the second feedback signal is a low-level pulse signal in the continuous three pulse times, it is judged that the servo drive braking circuit is in a fourth abnormal state, a fault warning is issued and a fourth fault type is reported;

[0109] S33. If the second feedback signal is a pulse signal in which the low-level pulse signal and the high-level pulse signal are alternately changed in the continuous three pulse times, it is judged that the servo drive braking circuit is in a normal state, and the step S1 is returned to be executed.

[0110] Further, the third fault type is that an external braking resistor or a power MOS tube in the servo drive braking circuit is open.

[0111] Further, the fourth fault type is that a power MOS tube in the servo drive braking circuit is short-circuited.

[0112] The second feedback signal refers to an electrical signal output by the detection circuit according to the second detection signal sent by the master control chip and the state change of the braking circuit, which reflects the response of the braking circuit when receiving a specific test signal, and can be realized by the output signal of an optical coupling chip. The three pulse times refer to the level state of the second feedback signal in the corresponding three unit pulse time periods during the sending of the second detection signal (for example, a low-high alternating pulse in three unit pulse times) by the master control chip. The high-level pulse signal refers to the voltage of the second feedback signal in a specific pulse time period. The low-level pulse signal refers to the voltage of the second feedback signal in a specific pulse time period. The third abnormal state refers to a specific fault mode of the servo drive braking circuit, corresponding to the case that the second feedback signal is a high-level pulse signal in the continuous three pulse times. The third fault type refers to a specific fault category corresponding to the third abnormal state, for example, an external braking resistor or a power MOS tube open. The fourth abnormal state refers to another specific fault mode of the servo drive braking circuit, corresponding to the case that the second feedback signal is a low-level pulse signal in the continuous three pulse times. The fourth fault type refers to a specific fault category corresponding to the fourth abnormal state, for example, a power MOS tube short circuit. The normal state refers to the normal function of the servo drive braking circuit, which can work according to the design requirements.

[0113] Specifically, when the bus voltage of the servo driver is lower than the preset brake function closing threshold, the system enters the brake circuit state detection flow in the non-braking state. The main control chip sends a specific second detection signal (for example, a low-high alternating pulse sequence) to the drive circuit, and the drive circuit attempts to control the state of the power MOS tube according to the signal. The detection circuit monitors the state change of the brake circuit (for example, by monitoring the voltage change on the state detection resistor), and converts the state change into a second feedback signal output to the main control chip. The main control chip receives and analyzes the level pattern of the second feedback signal in the continuous three pulse times. If the signal level in the three pulse times is all high, it indicates that the brake circuit is in the third abnormal state, and the system will issue a fault warning and report the third fault type. If the signal level in the three pulse times is all low, it indicates that the brake circuit is in the fourth abnormal state, and the system will issue a fault warning and report the fourth fault type. If the signal level in the three pulse times presents a low-high alternating pattern corresponding to the second detection signal pattern sent by the main control chip, it is judged that the brake circuit is in a normal state. After judging that it is in a normal state, since the bus voltage is lower than the brake function closing threshold, there is no need to perform brake operation, and the system returns to the initial step of periodically sampling the bus voltage, continues to monitor the bus voltage, and waits for the next judgment whether to start braking. In this way, even when braking is not needed, the system can actively detect potential faults of the brake circuit, especially those that may cause continuous conduction, thereby improving the reliability of the system. This detection mechanism utilizes the state detection resistor and detection circuit added in the servo drive brake circuit, and combines the ability of the main control chip to send test signals and receive feedback signals, making it possible to perform fault diagnosis in the non-braking state.

[0114] Specifically, the specific cause analysis of the third abnormal state is the same as the specific cause analysis of the first abnormal state in the above embodiment, which will not be repeated here.

[0115] Specifically, the specific cause analysis of the fourth abnormal state is the same as the specific cause analysis of the second abnormal state in the above embodiment, which will not be repeated here.

[0116] In this document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any such actual relationship or order between such entities or actions.

[0117] Reference to terms "one implementation", "some implementations", "certain implementations", "an example", "a specific example", or "some examples" etc., mean that a particular feature, structure, material or characteristic being described is included in at least one implementation or example of the present application. Such appearances of these terms in this specification are not necessarily referring to the same implementation or example. Furthermore, the described features, structures, materials or characteristics can be combined in any suitable manner in one or more implementations or examples.

[0118] The above descriptions are only some embodiments of the present application, and are not used to limit the protection scope of the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A servo drive control method, applied to a servo drive brake circuit, characterized in that: The servo drive braking circuit comprises a main circuit (100) and a drive circuit (200), wherein the drive circuit (200) is connected to the main circuit (100) and is used to drive a servo driver connected to the main circuit (100) to brake, and further comprises a main control chip (300) and a detection circuit (400), wherein the main circuit comprises a power MOS tube (Q), a freewheeling diode (Dx), a state detection resistor (Ra), and an external braking resistor (Rb); The gate of the power MOS tube (Q) is connected to the drive circuit (200); the source of the power MOS tube (Q) is connected to one end of the state detection resistor (Ra), and the other end of the state detection resistor (Ra) is connected to one end of the servo driver; the source of the power MOS tube (Q) is also connected to the detection circuit (400), the drain of the power MOS tube (Q) is simultaneously connected to the positive electrode of the freewheeling diode (Dx) and one end of the external braking resistor (Rb), and the other end of the external braking resistor (Rb) is simultaneously connected to the negative electrode of the freewheeling diode (Dx) and the other end of the servo driver; the detection circuit (400) can communicate with the drive circuit (200) through the main control chip (300); The servo drive control method comprises the following steps: S1. Periodically sample the bus voltage of the servo drive; S2. Compare the bus voltage of the servo driver with a preset brake function activation threshold. If the bus voltage of the servo driver is greater than or equal to the brake function activation threshold, control the main control chip to send a first detection signal to cause the detection circuit to output a first feedback signal, and determine the state of the servo drive brake circuit based on the first feedback signal and perform a corresponding action; the first detection signal is a pulse signal in which a low-level pulse signal and a high-level pulse signal alternate according to a unit pulse time; S3. Comparing the bus voltage of the servo driver with a preset brake function shutdown threshold; if the bus voltage of the servo driver is less than the brake function shutdown threshold, controlling the main control chip to send a second detection signal to cause the detection circuit to output a second feedback signal, and determining the state of the servo drive brake circuit based on the second feedback signal, and executing a corresponding action; the second detection signal is a pulse signal in which a low-level pulse signal and a high-level pulse signal alternate according to a unit pulse time; In step S2, the step of determining the state of the servo drive brake circuit according to the first feedback signal and executing a corresponding action includes: S21. If three consecutive pulses of the first feedback signal are high-level pulse signals, it is determined that the servo drive brake circuit is in a first abnormal state, a fault warning is issued and the first fault type is reported; S22. If three consecutive pulses of the first feedback signal are low-level pulse signals, it is determined that the servo drive brake circuit is in a second abnormal state, a fault warning is issued and the second fault type is reported; S23. If the first feedback signal has three consecutive pulses of a low-level pulse signal and a high-level pulse signal alternating between the pulse signal, it is determined that the servo drive brake circuit is in a normal state and the braking function is turned on; In step S3, the step of determining the state of the servo drive brake circuit according to the second feedback signal and executing a corresponding action includes: S31. If three consecutive pulses of the second feedback signal are high-level pulse signals, it is determined that the servo drive brake circuit is in a third abnormal state, a fault warning is issued and a third fault type is reported; S32. If three consecutive pulses of the second feedback signal are low-level pulse signals, it is determined that the servo drive brake circuit is in a fourth abnormal state, a fault warning is issued and a fourth fault type is reported; S33. If the three consecutive pulse times of the second feedback signal are pulse signals in which low-level pulse signals and high-level pulse signals alternate, it is determined that the servo drive brake circuit is in a normal state, and the process returns to step S1.

2. The servo drive control method according to claim 1, wherein: The first fault type and the third fault type are both caused by an open circuit of an external braking resistor or a power MOS tube in the servo drive braking circuit.

3. The servo drive control method according to claim 1, wherein: The second fault type and the fourth fault type are both caused by a short circuit of a power MOS tube in the servo drive brake circuit.

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