Servo driver and control method and device thereof, controller, robot and medium

Abstract

The application provides a servo driver, a control method and device thereof, a controller, a robot and a medium. The servo driver comprises a turn-off power module, a regenerative resistor, a DC bus capacitor, an inverter module and a motor, wherein the power module is connected with the regenerative resistor, the DC bus capacitor and the inverter module, and the inverter module is further connected with the motor; the control method comprises: in the case that a dynamic braking instruction is received, the power module is controlled to stop charging the DC bus capacitor; the inverter module is turned off, so that the motor charges the DC bus capacitor through the inverter module; the regenerative resistor is controlled to be turned on until the rotating speed of the motor is less than a first threshold value, and then the regenerative resistor is controlled to be turned off. In this way, the dynamic braking torque can be improved without increasing the hardware cost, the shutdown distance and time of the servo driver during dynamic braking are reduced, and the dynamic braking of the servo driver can also be realized in the case that the inverter module driving fails.

Description

Technical Field

[0001] This invention relates to the field of robotics, and more specifically, to a servo driver and its control method and apparatus, a controller, a robot, and a medium. Background Technology

[0002] In robot control systems, stop0 typically refers to an emergency stop mode, also known as a hard stop. Stop0 is usually used to immediately stop the robot in emergency situations, such as when safety protection is triggered, collision detection occurs, or the emergency stop button is pressed, as well as in safety protection situations, such as when potential harm to personnel or equipment is detected.

[0003] Currently, robots typically use a combination of dynamic braking and mechanical brakes to achieve Stop 0, relying on dynamic braking torque and mechanical brake friction to stop the robot. Dynamic braking generally has two implementation schemes: one scheme, such as... Figure 3 As shown, the robot control system opens the upper or lower bridge arm of the inverter module in the servo driver, achieving dynamic braking based on the short circuit of the inverter module's bridge arm. The advantages of this approach are that it does not require additional hardware, has a fast response speed, and can use PWM (Pulse Width Modulation) to modulate the braking current to protect the motor from overload. Its disadvantage is that if the inverter module driver fails, such as a fault in the inverter module's drive circuit or a power outage, or if the controller is completely powered off, dynamic braking cannot be achieved. Another approach, such as... Figure 4 As shown, dynamic braking is achieved by short-circuiting the three-phase power lines of the motor through an external relay, such as a dynamic braking relay, and de-energizing the relay. The advantage of this scheme is that dynamic braking can be achieved even when the controller is completely de-energized. However, its disadvantages include slow response speed, increased hardware cost, increased size, uncontrollable braking current, and the relay being prone to failure. Furthermore, when the motor is working normally, the external relay needs to be continuously energized, which increases the heat generation and power consumption of the controller.

[0004] Therefore, the above-mentioned dynamic braking schemes either have the risk of failure or require the addition of extra components, resulting in high hardware costs and susceptibility to the influence of these extra components. The stability of dynamic braking is also poor. Furthermore, when the motor speed is high, the torque of dynamic braking is relatively small, making it impossible to quickly reduce the motor speed, resulting in low efficiency of dynamic braking. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0006] Therefore, the first aspect of the present invention is to provide a control method for a servo driver.

[0007] A second aspect of the present invention is to provide a control device for a servo driver.

[0008] The third aspect of the present invention is to provide a servo driver.

[0009] A fourth aspect of the invention is to provide a controller.

[0010] The fifth aspect of this invention is to provide an industrial robot.

[0011] The sixth aspect of the present invention is to provide a readable storage medium.

[0012] In view of this, according to a first aspect of the present invention, a control method for a servo driver is proposed. The servo driver includes a power supply module that can be turned off, a regenerative resistor, a DC bus capacitor, an inverter module, and a motor. The power supply module is connected to the regenerative resistor, the DC bus capacitor, and the inverter module, and the inverter module is also connected to the motor. The control method includes: upon receiving a dynamic braking command, controlling the power supply module to stop charging the DC bus capacitor; turning off the inverter module to allow the motor to charge the DC bus capacitor through the inverter module; controlling the regenerative resistor to conduct until the motor speed is less than a first threshold, and then controlling the regenerative resistor to disconnect.

[0013] The execution subject of the servo drive control method provided by this invention can be the servo drive control device, or it can be determined according to actual usage requirements, and is not specifically limited here. To more clearly describe the servo drive control method provided by this invention, the following description uses the servo drive control device as the execution subject.

[0014] The servo driver control method provided by this invention is used to control the servo driver to perform dynamic braking.

[0015] Specifically, the aforementioned servo driver may include a power supply module that can be turned off, a DC bus capacitor, a regenerative resistor, a motor, and an inverter module.

[0016] The power supply module is connected to the DC bus capacitor, regenerative resistor, and inverter module. The inverter module is also connected to the motor.

[0017] Specifically, in the servo drive control method provided by this invention, when the robot control system needs to enter stop0 mode due to certain faults or emergencies, the robot control system sends a dynamic braking command. The servo drive control device receives the dynamic braking command and, based on the command, controls the servo drive to perform dynamic braking. Specifically, after receiving the dynamic braking command, the servo drive control device shuts down the power module to stop it from working and charging the DC bus capacitor. Simultaneously, the servo drive control device immediately shuts down the inverter module, turning it into an uncontrolled three-phase rectifier bridge. At this time, the motor is in a generating state, and the inverter module, through its internal diodes, can achieve uncontrolled rectification of the motor's output current. That is, the current inverter module is equivalent to a general rectifier bridge, and the motor can begin charging the DC bus capacitor through the inverter module. Furthermore, to quickly dissipate regenerative energy while preventing a continuous rise in the DC bus capacitor voltage, the servo drive's control unit immediately activates the regenerative resistor after the inverter module is shut down. This releases the regenerative energy by generating heat through the regenerative resistor until the motor speed drops to a sufficiently low level or the motor stops rotating—that is, until the motor speed falls below a preset first threshold. At this point, the servo drive's control unit then disconnects the regenerative resistor to prepare for the next motor start-up. This eliminates the need for additional relays, enabling dynamic braking of the servo drive even in the event of an inverter module failure. This improves the stability of dynamic braking, reduces hardware costs, and, by rapidly dissipating regenerative energy through the regenerative resistor, increases the dynamic braking torque, reduces the stopping distance and time for dynamic braking, and improves the efficiency of dynamic braking.

[0018] In some technical solutions, the servo driver may optionally include a switching transistor connected to both the regenerative resistor and the power module, controlling the regenerative resistor to conduct, including: controlling the switching transistor to conduct so as to conduct the regenerative resistor; wherein the signal duty cycle of the switching transistor gradually increases from 0 to 100%.

[0019] In this technical solution, the aforementioned servo driver may further include a switching transistor.

[0020] The first terminal of the switching transistor is connected to the regenerative resistor, and the second terminal of the switching transistor is connected to the power module.

[0021] Based on this, during the process of the servo drive's control device turning on the regenerative resistor, the control device specifically turns on the regenerative resistor by turning on the switching transistor. Specifically, during this process, the control device gradually turns on the switching transistor by increasing the signal duty cycle from 0 to 100%, until the transistor is fully turned on. This gradual increase in the switching transistor's signal duty cycle, by turning on the regenerative resistor, limits the braking torque and the motor's phase current. This avoids motor and regenerative resistor surges caused by instantaneous switching on, as well as braking torque surges caused by instantaneous switching on, thus achieving controllable braking torque and preventing mechanical shocks caused by excessive braking torque at the moment of entering dynamic braking.

[0022] In some technical solutions, the control method of the servo driver may optionally include: calculating the power consumption of the regenerative resistor; determining the average power of the regenerative resistor based on the power consumption; and reducing the signal duty cycle of the switching transistor when the average power is greater than a second threshold.

[0023] In this technical solution, during the dynamic braking process of the servo drive, the servo drive's control device also calculates the energy consumption of the regenerative resistor in real time, and then monitors the average power of the regenerative resistor based on the calculated energy consumption. Furthermore, if the servo drive's control device detects that the average power of the regenerative resistor exceeds a preset second threshold, it will reduce the conduction current of the regenerative resistor by decreasing the signal duty cycle of the switching transistor, thereby limiting the average power of the regenerative resistor. This prevents overload of the regenerative resistor, protects it, and extends its service life.

[0024] In some technical solutions, optionally, the energy consumption of the regenerative resistor is calculated, including: calculating the energy consumption of the regenerative resistor according to the following formula: E=(V1 2 ×t) / R; where E is the consumed electrical energy, V1 is the nominal voltage of the DC bus capacitor, t is the conduction time of the switching transistor, and R is the nominal resistance of the regenerative resistor.

[0025] In this technical solution, during the process of the servo drive's control device calculating the energy consumption of the regenerative resistor, the servo drive's control device can specifically obtain the nominal voltage of the DC bus capacitor, the conduction time of the switching transistor, and the nominal resistance value of the regenerative resistor, and then calculate the energy consumption of the regenerative resistor in real time according to the following formula (1):

[0026] E = (V1) 2 ×t) / R,(1)

[0027] Where E represents the energy consumed by the regenerative resistor, t represents the conduction time of the switching transistor, V1 represents the nominal voltage of the DC bus capacitor, and R represents the nominal resistance of the regenerative resistor.

[0028] In this way, the energy consumption of the regenerative resistor can be calculated using a fixed reference value, eliminating the need for additional calculations and simplifying the process.

[0029] In some technical solutions, optionally, the energy consumption of the regenerative resistor is calculated, including: calculating the energy consumption of the regenerative resistor according to the following formula: E=(V2 2 ×t) / R; where E is the consumed electrical energy, V2 is the real-time voltage of the DC bus capacitor, t is the conduction time of the switching transistor, and R is the nominal resistance of the regenerative resistor.

[0030] In this technical solution, during the process of the servo drive's control device calculating the energy consumption of the regenerative resistor, the servo drive's control device can specifically obtain the nominal voltage of the DC bus capacitor, the conduction time of the switching transistor, and the nominal resistance value of the regenerative resistor, and then calculate the energy consumption of the regenerative resistor in real time according to the following formula (2):

[0031] E = (V2) 2 ×t) / R,(2)

[0032] Where E represents the energy consumed by the regenerative resistor, t represents the conduction time of the switching transistor, V2 represents the real-time voltage of the DC bus capacitor, and R represents the nominal resistance value of the regenerative resistor.

[0033] In this way, by combining the real-time status of the DC bus capacitor, the energy consumption of the regenerative resistor can be calculated. While ensuring the simplicity of the calculation, the accuracy of the energy consumption calculation is improved, thereby ensuring the accuracy of dynamic braking control.

[0034] In some technical solutions, the control method of the servo driver may optionally include: detecting the phase current of the motor; and reducing the signal duty cycle of the switching transistor when the phase current of the motor is greater than the maximum current of the motor.

[0035] In this technical solution, during the dynamic braking process of the servo driver, the servo driver's control device also monitors the phase current of the motor in real time. If it detects that one or more phase currents of the motor exceed the maximum current of the motor, the servo driver's control device will reduce the phase current of the motor by reducing the signal duty cycle of the switching transistors. This can prevent motor damage caused by excessive phase current and also improve the linearity between braking torque and motor speed during braking, thus achieving dynamic braking torque control.

[0036] In some technical solutions, the signal duty cycle of the switching transistor can be optionally reduced, including: reducing the signal duty cycle of the switching transistor through a closed-loop control algorithm; or, reducing the signal duty cycle of the switching transistor according to a preset duty cycle adjustment strategy.

[0037] In this technical solution, the servo drive's control device can reduce the signal duty cycle of the switching transistor using a closed-loop control algorithm. Furthermore, the servo drive's control device can also test and calibrate the switching transistor's signal duty cycle beforehand, and then reduce the signal duty cycle according to a preset duty cycle adjustment strategy. This improves the versatility of duty cycle adjustment.

[0038] In some technical solutions, the control method of the servo driver may optionally include: reducing the difference between the motor's line current and peak current, provided that the motor's line current is less than the motor's peak current.

[0039] In this technical solution, during motor deceleration, the servo driver's control device minimizes the difference between the motor's line current and peak current while ensuring that the motor's line current does not exceed its peak current, thereby maximizing the line current to reach the peak current. This achieves maximum braking torque without damaging the motor.

[0040] In some technical solutions, optionally, controlling the power module to stop charging the DC bus capacitor includes: if the power module includes an AC power supply and a fully controlled rectifier bridge, controlling the fully controlled rectifier bridge to turn off; if the power module is a turn-off DC power supply, controlling the DC power supply to turn off; if the power module is a turn-off battery, controlling the battery to turn off.

[0041] In this technical solution, the power module may specifically include a fully controlled rectifier bridge and an AC power supply. In this case, the servo driver's control device can control the power module to stop charging the DC bus capacitor by controlling the fully controlled rectifier bridge to shut down. Furthermore, the power module may also be a switchable DC power supply. In this case, the servo driver's control device can directly control the DC power supply to shut down, thereby stopping the DC bus capacitor from charging. Further still, the power module may also be a switchable battery. In this case, the servo driver's control device can directly control the battery to shut down, thereby stopping the battery from charging the DC bus capacitor. This improves the versatility of power module shutdown control.

[0042] According to a second aspect of the present invention, a control device for a servo driver is provided. The servo driver includes a power supply module that can be turned off, a regenerative resistor, a DC bus capacitor, an inverter module, and a motor. The power supply module is connected to the regenerative resistor, the DC bus capacitor, and the inverter module, and the inverter module is also connected to the motor. The control device includes: a control unit for controlling the power supply module to stop charging the DC bus capacitor upon receiving a dynamic braking command; the control unit is also used to turn off the inverter module so that the motor charges the DC bus capacitor through the inverter module; and the control unit is also used to control the regenerative resistor to be turned on until the motor speed is less than a first threshold, and then control the regenerative resistor to be turned off.

[0043] The servo driver control device provided by the present invention is used to control the servo driver to perform dynamic braking.

[0044] Specifically, the aforementioned servo driver may include a power supply module that can be turned off, a DC bus capacitor, a regenerative resistor, a motor, and an inverter module.

[0045] The power supply module is connected to the DC bus capacitor, regenerative resistor, and inverter module. The inverter module is also connected to the motor.

[0046] Specifically, the control device for the servo drive provided by this invention includes a control unit. When the robot control system needs to enter stop0 mode due to certain faults or emergencies, the robot control system sends a dynamic braking command. The control unit receives the dynamic braking command and, based on the command, controls the servo drive to perform dynamic braking. Specifically, after receiving the dynamic braking command, the control unit shuts down the power module to stop its operation and cease charging the DC bus capacitor. Simultaneously, the control unit immediately shuts down the inverter module, turning it into an uncontrolled three-phase rectifier bridge. At this time, the motor is in a generating state, and the inverter module, through its internal diodes, can achieve uncontrolled rectification of the motor's output current. That is, the current inverter module is equivalent to a general rectifier bridge, and the motor can begin charging the DC bus capacitor through the inverter module. Furthermore, to quickly dissipate regenerative energy while preventing a continuous rise in the DC bus capacitor voltage, the control unit immediately activates the regenerative resistor after the inverter module is shut down. This releases the regenerative energy by generating heat through the regenerative resistor until the motor speed drops to a sufficiently low level or the motor stops rotating—that is, until the motor speed falls below a preset first threshold. At this point, the control unit then disconnects the regenerative resistor to prepare for the next motor start-up. This eliminates the need for additional relays, enabling dynamic braking of the servo drive even in the event of an inverter module failure. This improves the stability of dynamic braking, reduces hardware costs, and, by rapidly dissipating regenerative energy through the regenerative resistor, increases the dynamic braking torque, reduces the stopping distance and time for dynamic braking, and improves the efficiency of dynamic braking.

[0047] According to a third aspect of the present invention, a servo driver is provided, comprising: a memory storing a program or instructions; and a processor, wherein the processor executes the program or instructions to implement the steps of the servo driver control method as described in any of the above-described technical solutions. Therefore, the servo driver proposed in the third aspect of the present invention possesses all the beneficial effects of the servo driver control method in any of the technical solutions of the first aspect described above, and will not be elaborated further here.

[0048] According to a fourth aspect of the present invention, a controller is provided, comprising the servo driver described in the third aspect of the technical solution above. The controller proposed in the fourth aspect of the present invention includes the servo driver described in the third aspect of the technical solution above. Therefore, the controller proposed in the fourth aspect of the present invention possesses all the beneficial effects of the servo driver described in the third aspect of the technical solution above, which will not be elaborated further here.

[0049] According to a fifth aspect of the present invention, an industrial robot is provided, comprising: the controller described in the fourth aspect of the technical solution above. The industrial robot proposed in the fifth aspect of the present invention includes the controller described in the fourth aspect of the technical solution above. Therefore, the industrial robot proposed in the fifth aspect of the present invention possesses all the beneficial effects of the controller described in the fourth aspect of the technical solution above, which will not be elaborated further here.

[0050] According to a sixth aspect of the present invention, a readable storage medium is provided on which a program or instructions are stored, which, when executed by a processor, implement the control method of the servo driver as described in any of the above-described technical solutions. Therefore, the readable storage medium proposed in the sixth aspect of the present invention possesses all the beneficial effects of the control method of the servo driver in any of the technical solutions of the first aspect, and will not be elaborated further here.

[0051] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0052] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0053] Figure 1 A flowchart illustrating the control method of the servo driver according to an embodiment of the present invention is shown;

[0054] Figure 2 A circuit structure diagram of a servo driver according to an embodiment of the present invention is shown;

[0055] Figure 3 One of the circuit structure diagrams of a servo driver in the related art is shown;

[0056] Figure 4 The second circuit diagram of a servo driver in the related technology is shown;

[0057] Figure 5 One of the comparison charts of dynamic braking effects is shown;

[0058] Figure 6 The second comparison chart of dynamic braking effects is shown;

[0059] Figure 7 The third comparison chart of dynamic braking effects is shown;

[0060] Figure 8 A structural block diagram of the control device for the servo driver according to an embodiment of the present invention is shown;

[0061] Figure 9 A structural block diagram of a servo driver according to an embodiment of the present invention is shown;

[0062] Figure 10 A structural block diagram of the controller according to an embodiment of the present invention is shown;

[0063] Figure 11 A structural block diagram of an industrial robot according to an embodiment of the present invention is shown. Detailed Implementation

[0064] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0065] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0066] The following is combined Figures 1 to 11 The servo driver and its control method and device, controller, robot and medium provided in this application will be described in detail through specific embodiments and application scenarios.

[0067] In one embodiment of the present invention, such as Figure 1 As shown, the control method for the servo driver may specifically include the following steps 102 to 106:

[0068] Step 102: Upon receiving a dynamic braking command, control the power module to stop charging the DC bus capacitor;

[0069] Step 104: Turn off the inverter module so that the motor can charge the DC bus capacitor through the inverter module;

[0070] Step 106: Control the regenerative resistor to conduct until the motor speed is less than the first threshold, then control the regenerative resistor to disconnect.

[0071] The execution subject of the servo drive control method provided by this invention can be the servo drive control device, or it can be determined according to actual usage requirements, and is not specifically limited here. To more clearly describe the servo drive control method provided by this invention, the following description uses the servo drive control device as the execution subject.

[0072] The servo driver control method provided by this invention is used to control the servo driver to perform dynamic braking.

[0073] Among them, such as Figure 2As shown, the aforementioned servo driver may specifically include a power-off module, a DC bus capacitor, a regenerative resistor, a motor, and an inverter module.

[0074] The power supply module is connected to both ends of the DC bus capacitor, the first end of the regenerative resistor, and both ends of the inverter module. The first end of the regenerative resistor is also connected to the first end of the DC bus capacitor. The inverter module is connected in parallel with the DC bus capacitor and is also connected to the motor.

[0075] In practical applications, the aforementioned power module may include a fully controlled rectifier bridge and an AC power supply. It may also be a switchable DC power supply or a switchable battery. Those skilled in the art can select the specific configuration of the power module according to actual circumstances, and no specific limitations are imposed here.

[0076] Furthermore, in practical applications, the inverter module described above can be a rectifier bridge composed of six IGBTs (Insulated Gate Bipolar Transistors), without any specific restrictions.

[0077] Specifically, in the servo drive control method provided by this invention, when the robot control system needs to enter stop0 mode due to certain faults or emergencies, the robot control system sends a dynamic braking command. The servo drive control device receives the dynamic braking command and, based on the command, controls the servo drive to perform dynamic braking. Specifically, after receiving the dynamic braking command, the servo drive control device shuts down the power module to stop it from working and charging the DC bus capacitor. Simultaneously, the servo drive control device immediately shuts down the inverter module, turning it into an uncontrolled three-phase rectifier bridge. At this time, the motor is in a generating state, and the inverter module, through its internal diodes, can achieve uncontrolled rectification of the motor's output current. That is, the current inverter module is equivalent to a general rectifier bridge, and the motor can begin charging the DC bus capacitor through the inverter module. Furthermore, to quickly dissipate regenerative energy while preventing a continuous rise in the DC bus capacitor voltage, the servo drive's control unit immediately activates the regenerative resistor after the inverter module is shut down. This releases the regenerative energy by generating heat through the regenerative resistor until the motor speed drops to a sufficiently low level or the motor stops rotating—that is, until the motor speed falls below a preset first threshold. At this point, the servo drive's control unit then disconnects the regenerative resistor to prepare for the next motor start-up. This eliminates the need for additional relays, enabling dynamic braking of the servo drive even in the event of an inverter module failure. This improves the stability of dynamic braking, reduces hardware costs, and, by rapidly dissipating regenerative energy through the regenerative resistor, increases the dynamic braking torque, reduces the stopping distance and time for dynamic braking, and improves the efficiency of dynamic braking.

[0078] The specific value of the first threshold can be set by those skilled in the art according to the actual situation, and no specific restrictions are imposed here.

[0079] Understandably, the Stop 0 mode in a robot control system has the following characteristics: Immediate stop: The robot immediately stops all movement, regardless of its current speed and position; High priority: Typically used in emergencies, such as safety protection triggers or collision detection; Risk of impact: Due to the immediate stop, it may cause significant mechanical impact on the robot and load; Complex recovery: The robot needs to be reset and recalibrated after stopping to ensure a safe restart. The stopping distance and stopping time are important parameters of the Stop 0 mode. For example, the stopping distance and stopping time of the first three axes of a six-axis industrial robot in Stop 0 mode are shown in Table 1 below. The shorter the stopping distance and stopping time in Stop 0 mode, the less likely a collision will occur when the robot stops, and the higher the safety of the robot control system.

[0080] Table 1: Example Table of Stopping Distance and Stopping Time

[0081] Stopping distance (°) Downtime (s) Shaft 1 34.13 0.22 Axis 2 21.45 0.18 Axis 3 32.87 0.19

[0082] However, the braking schemes in related technologies have relatively low dynamic braking torque at high motor speeds, resulting in longer stopping distances and times, thus failing to quickly reduce motor speed and leading to low efficiency in dynamic braking. Furthermore, these braking schemes cannot achieve dynamic braking in the event of inverter module drive failure or complete controller power failure, exhibiting poor stability and requiring additional relays, which increases hardware costs.

[0083] Therefore, in the servo driver control method provided by this invention, no additional relays are used; instead, regenerative resistors and a power supply module that can be turned off are employed. During dynamic braking, by turning off the power supply module and the IGBTs in the inverter module, the diodes in the inverter module rectify the motor output current. Even when the inverter module cannot drive normally, such as in the case of a fault in the inverter module's drive circuit, a power outage in the inverter module's drive circuit, or a complete power outage of the controller, dynamic braking of the servo driver can still be achieved, improving the stability of dynamic braking. Furthermore, by replacing the motor winding resistor with a regenerative resistor, the regenerative energy during the motor deceleration process can be consumed more concentratedly and efficiently, increasing the dynamic braking torque, reducing the stopping distance and time of the servo driver during dynamic braking, and improving the efficiency of dynamic braking.

[0084] In practical applications, when the motor's back electromotive force (EMF) is higher than the DC bus capacitor voltage, the servo driver can be decelerated and braked by shutting down the servo driver's IPM (Intelligent Power Module). In this case, the deceleration energy is recovered by the DC bus capacitor, causing its voltage to rise. Once the DC bus capacitor voltage exceeds the motor's back EMF, the motor's braking torque becomes zero, and the motor can only stop due to friction.

[0085] In some embodiments of the present invention, the servo driver may optionally include a switching transistor connected to both the regenerative resistor and the power module. The step of controlling the regenerative resistor to conduct may specifically include the following step 108:

[0086] Step 108: Control the switching transistor to turn on, so as to turn on the regenerative resistor;

[0087] The signal duty cycle of the switching transistor gradually increases from 0 to 100%.

[0088] In this embodiment, such as Figure 2As shown, the aforementioned servo driver may also include a switching transistor.

[0089] The first terminal of the switching transistor is connected to the second terminal of the regenerative resistor, and the second terminal of the switching transistor is connected to the power module.

[0090] Furthermore, the switching transistor is used to control whether the regenerative resistor is turned on, and it is also used to control the magnitude of the regenerative resistor's on-state current.

[0091] Based on this, during the process of the servo drive's control device turning on the regenerative resistor, the control device specifically turns on the regenerative resistor by turning on the switching transistor. Specifically, during this process, the control device gradually turns on the switching transistor by increasing the signal duty cycle from 0 to 100%, until the transistor is fully turned on. This gradual increase in the switching transistor's signal duty cycle, by turning on the regenerative resistor, limits the braking torque and the motor's phase current. This avoids motor and regenerative resistor surges caused by instantaneous switching on, as well as braking torque surges caused by instantaneous switching on, thus achieving controllable braking torque and preventing mechanical shocks caused by excessive braking torque at the moment of entering dynamic braking.

[0092] In practical applications, the aforementioned switching transistors can be IGBT transistors, MOS (Metal-Oxide-Semiconductor) transistors, etc., without specific limitations.

[0093] Furthermore, after the motor speed drops to a sufficiently low speed, or after the motor stops rotating, that is, after the motor speed drops below a preset first threshold, the servo driver's control device will control the switching transistor to turn off, so that the regenerative resistor is disconnected, in order to prepare for the next motor start-up.

[0094] In some embodiments of the present invention, the control method may optionally include the following steps 110 to 114:

[0095] Step 110: Calculate the electrical energy consumed by the regenerative resistor;

[0096] Step 112: Determine the average power of the regenerative resistor based on the consumed electrical energy;

[0097] Step 114: If the average power is greater than the second threshold, reduce the signal duty cycle of the switching transistor.

[0098] In this embodiment, during the dynamic braking process of the servo drive, the servo drive's control device also calculates the energy consumption of the regenerative resistor in real time, and then monitors the average power of the regenerative resistor in real time based on the calculated energy consumption. Furthermore, if the servo drive's control device detects that the average power of the regenerative resistor exceeds a preset second threshold, the control device will reduce the conduction current of the regenerative resistor by decreasing the signal duty cycle of the switching transistor, thereby limiting the average power of the regenerative resistor. This prevents overload of the regenerative resistor, protects it, and extends its service life.

[0099] The specific value of the second threshold can be set by those skilled in the art according to the actual situation, and no specific restrictions are imposed here.

[0100] In some embodiments of the present invention, step 110 may optionally include step 116 as follows:

[0101] Step 116, according to the formula E = (V1) 2 Calculate the electrical energy consumed by the regenerative resistor using (×t) / R;

[0102] Where E represents the energy consumed by the regenerative resistor, t represents the conduction time of the switching transistor, V1 represents the nominal voltage of the DC bus capacitor, and R represents the nominal resistance of the regenerative resistor.

[0103] In this embodiment, during the process of the servo drive's control device calculating the energy consumption of the regenerative resistor, the servo drive's control device can specifically obtain the nominal voltage of the DC bus capacitor, the conduction time of the switching transistor, and the nominal resistance value of the regenerative resistor, and then calculate the energy consumption of the regenerative resistor in real time according to the following formula (1):

[0104] E = (V1) 2 ×t) / R,(1)

[0105] Where E represents the energy consumed by the regenerative resistor, t represents the conduction time of the switching transistor, V1 represents the nominal voltage of the DC bus capacitor, and R represents the nominal resistance of the regenerative resistor.

[0106] In this way, the energy consumption of the regenerative resistor can be calculated using a fixed reference value, eliminating the need for additional calculations and simplifying the process.

[0107] In some embodiments of the present invention, step 110 may optionally include step 118 as follows:

[0108] Step 118, according to the formula E = (V2) 2 Calculate the electrical energy consumed by the regenerative resistor using (×t) / R;

[0109] Where E represents the energy consumed by the regenerative resistor, t represents the conduction time of the switching transistor, V2 represents the real-time voltage of the DC bus capacitor, and R represents the nominal resistance value of the regenerative resistor.

[0110] In this embodiment, during the process of the servo driver's control device calculating the energy consumption of the regenerative resistor, the servo driver's control device can specifically obtain the nominal voltage of the DC bus capacitor, the conduction time of the switching transistor, and the nominal resistance value of the regenerative resistor, and then calculate the energy consumption of the regenerative resistor in real time according to the following formula (2):

[0111] E = (V2) 2 ×t) / R,(2)

[0112] Where E represents the energy consumed by the regenerative resistor, t represents the conduction time of the switching transistor, V2 represents the real-time voltage of the DC bus capacitor, and R represents the nominal resistance value of the regenerative resistor.

[0113] In this way, by combining the real-time status of the DC bus capacitor, the energy consumption of the regenerative resistor can be calculated. While ensuring the simplicity of the calculation, the accuracy of the energy consumption calculation is improved, thereby ensuring the accuracy of dynamic braking control.

[0114] In some embodiments of the present invention, the control method may optionally include the following steps 120 and 122:

[0115] Step 120: Detect the phase current of the motor;

[0116] Step 122: If the phase current of the motor is greater than the maximum current of the motor, reduce the signal duty cycle of the switching transistor.

[0117] In this embodiment, during the dynamic braking process of the servo driver, the control device of the servo driver also monitors the phase current of the motor in real time. If it detects that one or more phase currents of the motor are greater than the maximum current of the motor, the control device of the servo driver will reduce the phase current of the motor by reducing the signal duty cycle of the switching transistor. This can prevent motor damage caused by excessive phase current and improve the linearity between braking torque and motor speed during braking, thus realizing dynamic braking torque control.

[0118] It is understandable that, ignoring losses such as those in the inverter module's diodes, based on the law of conservation of energy, the energy conservation relationship between the motor and the regenerative resistor during the dynamic braking process of the servo driver can be specifically expressed as the following formula (3):

[0119] (J×w 2 ) / 2=I 2 ×R×t,(3)

[0120] In formula (3), the left side represents the kinetic energy of the motor during rotation, where J represents the moment of inertia of the motor, which reflects the magnitude of the inertia of the object during rotation, and w represents the angular velocity of the motor, which represents the speed of the motor's rotation. Furthermore, the phase current of the motor is positively correlated with the kinetic energy of the motor during rotation.

[0121] Furthermore, the right-hand side of formula (3) represents the electrical energy consumed by the regenerative resistor, where I represents the conduction current of the regenerative resistor, R represents the nominal resistance of the regenerative resistor, and t represents the conduction time of the switching transistor. Based on this, formula (3) indicates that, ignoring losses such as those of diodes in the inverter module, all the kinetic energy of the motor during rotation is converted into electrical energy consumed by the regenerative resistor.

[0122] As can be seen from formula (3), by reducing the signal duty cycle of the switching transistor connected to the regenerative resistor, the conduction current I of the regenerative resistor can be reduced, thereby reducing the converted kinetic energy and thus reducing the phase current of the motor.

[0123] Therefore, during dynamic braking by the servo driver, when the phase current of the motor is large, the control device of the servo driver can reduce the phase current of the motor by reducing the signal duty cycle of the switching transistor.

[0124] Furthermore, it can be understood that in traditional dynamic braking schemes, the relationship between braking torque and motor speed is as follows: as the motor speed increases from 0, the braking torque first increases rapidly, then decreases, and finally converges to a fixed braking torque. Specifically, the relationship between braking torque and motor speed can be expressed by the following formula (4):

[0125]

[0126] Among them, T e p represents electromagnetic torque. n R represents the number of pole pairs of the motor, ω represents the motor speed, and R represents the motor speed. s ψ represents the stator resistance. f L represents magnetic flux linkage. d L represents the d-axis inductance. q This represents the q-axis inductance.

[0127] For the above formula (4), when the motor speed is low, if the motor speed satisfies L d L q ω 2 much smaller When it is, it can be simplified to the following formula (5):

[0128]

[0129] Furthermore, when the motor speed is high, such as when the motor speed satisfies L...d L q ω 2 Much larger When it is, it can be simplified to the following formula (6):

[0130]

[0131] As can be seen from the above formulas (4) to (6), in the traditional dynamic braking scheme, the dynamic braking torque and the motor speed have a nonlinear relationship, making dynamic braking torque control relatively difficult.

[0132] Furthermore, it can be understood that the braking effect of excessively low regenerative resistance is significantly different from the braking effect of moderate regenerative resistance. Figure 6 As shown, if the regenerative resistance is too small during the motor deceleration process, it can easily lead to excessive phase current in the motor. At the same time, the linearity between the dynamic braking torque and the motor speed will also deteriorate.

[0133] Therefore, in the servo driver control method provided by this invention, during the dynamic braking process of the servo driver, when the phase current of the motor is large, the control device of the servo driver limits the phase current and braking torque of the motor by reducing the signal duty cycle of the switching transistor. This avoids motor damage due to excessive phase current and improves the linearity between braking torque and motor speed during braking, making the change in braking torque more linear with motor speed; that is, the lower the motor speed, the lower the braking torque, thus achieving a smooth stop.

[0134] Furthermore, the braking effect of excessively high regenerative resistance is compared to the braking effect of moderately high regenerative resistance. Figure 7 As shown, if the regenerative resistance is too high during the motor deceleration process, no additional treatment is required.

[0135] In some embodiments of the present invention, optionally, the step of reducing the signal duty cycle of the switching transistor may specifically include step 124 or step 126 as follows:

[0136] Step 124: Reduce the signal duty cycle of the switching transistor using a closed-loop control algorithm;

[0137] Step 126: Reduce the signal duty cycle of the switching transistor according to the preset duty cycle adjustment strategy.

[0138] In this embodiment, the servo driver's control device can reduce the signal duty cycle of the switching transistor using a closed-loop control algorithm. Furthermore, the servo driver's control device can also test and calibrate the switching transistor's signal duty cycle beforehand, and then reduce the signal duty cycle according to a preset duty cycle adjustment strategy. This improves the versatility of duty cycle adjustment.

[0139] In practical applications, the aforementioned closed-loop control algorithm can specifically be a PID (Proportion-Integration-Differential) control algorithm. Those skilled in the art can select a specific closed-loop control algorithm according to the actual situation, and no specific restrictions are imposed here.

[0140] In some embodiments of the present invention, the control method may optionally include the following step 128:

[0141] Step 128: While controlling the motor's line current to be less than the motor's peak current, reduce the difference between the motor's line current and peak current.

[0142] In this embodiment, during motor deceleration, the servo driver's control device minimizes the difference between the motor's line current and peak current while ensuring that the motor's line current does not exceed its peak current, thereby maximizing the line current to reach the peak current. This achieves maximum braking torque without damaging the motor.

[0143] In some embodiments of the present invention, optionally, the step of controlling the power supply module to stop charging the DC bus capacitor may specifically include the following steps 130 to 134:

[0144] Step 130: If the power module includes an AC power supply and a fully controlled rectifier bridge, control the fully controlled rectifier bridge to shut down;

[0145] Step 132: If the power module is a switchable DC power supply, control the DC power supply to turn off;

[0146] Step 134: If the power module is a switchable battery, control the battery to turn off.

[0147] In this embodiment, the power module may specifically include a fully controlled rectifier bridge and an AC power supply. In this case, the servo driver's control device can control the power module to stop charging the DC bus capacitor by controlling the fully controlled rectifier bridge to shut down. Furthermore, the power module may also be a switchable DC power supply. In this case, the servo driver's control device can directly control the DC power supply to shut down, thereby stopping the DC bus capacitor from charging. Further, the power module may also be a switchable battery. In this case, the servo driver's control device can directly control the battery to shut down, thereby stopping the battery from charging the DC bus capacitor. This improves the versatility of power module shutdown control.

[0148] In summary, this invention provides a dynamic braking method based on a regenerative resistor and a switchable power module. The dynamic braking effect of traditional methods can be compared with that of this invention as follows: Figure 5 As shown, compared to traditional dynamic braking methods, such as Figure 5 As shown, the dynamic braking method of the present invention can quickly reduce the capacitor voltage of the DC bus capacitor, the motor speed, and the motor phase current, and can also improve the linearity between braking torque and motor speed.

[0149] In one embodiment of the present invention, a control device for a servo driver is also provided. For example... Figure 8 As shown, Figure 8 A structural block diagram of a servo driver control device 200 according to an embodiment of the present invention is shown. Specifically, the servo driver control device 200 may include a control unit 202:

[0150] The control unit 202 is used to control the power module to stop charging the DC bus capacitor when a dynamic braking command is received.

[0151] The control unit 202 is also used to shut down the inverter module so that the motor can charge the DC bus capacitor through the inverter module;

[0152] The control unit 202 is also used to control the regenerative resistor to conduct until the motor speed is less than the first threshold, and then control the regenerative resistor to disconnect.

[0153] The servo driver control device 200 provided in this embodiment of the invention is used to control the servo driver to perform dynamic braking.

[0154] Specifically, the aforementioned servo driver may include a power supply module that can be turned off, a DC bus capacitor, a regenerative resistor, a motor, and an inverter module.

[0155] The power supply module is connected to both ends of the DC bus capacitor, the first end of the regenerative resistor, and both ends of the inverter module. The first end of the regenerative resistor is also connected to the first end of the DC bus capacitor. The inverter module is connected in parallel with the DC bus capacitor and is also connected to the motor.

[0156] In practical applications, the aforementioned power module may include a fully controlled rectifier bridge and an AC power supply. It may also be a switchable DC power supply or a switchable battery. Those skilled in the art can select the specific configuration of the power module according to actual circumstances, and no specific limitations are imposed here.

[0157] Furthermore, in practical applications, the inverter module can be a rectifier bridge composed of 6 IGBTs, without any specific restrictions.

[0158] Specifically, the servo drive control device 200 provided by this invention includes a control unit 202. When the robot control system needs to enter the stop0 mode due to certain faults or emergencies, the robot control system will send a dynamic braking command. The control unit 202 receives the dynamic braking command and, based on the dynamic braking command, controls the servo drive to perform dynamic braking. Specifically, after receiving the dynamic braking command, the control unit 202 will shut down the power module to stop the power module from working and stop charging the DC bus capacitor. At the same time, the control unit 202 will immediately shut down the inverter module, turning the inverter module into an uncontrolled three-phase rectifier bridge. At this time, the motor is in a generating state, and the inverter module can realize uncontrolled rectification of the motor output current through its internal diodes. That is, the current inverter module is equivalent to a general rectifier bridge, and the motor can start charging the DC bus capacitor through the inverter module. Furthermore, to quickly dissipate regenerative energy while preventing a continuous rise in the DC bus capacitor voltage, the control unit 202 immediately activates the regenerative resistor after the inverter module is shut down. This releases the regenerative energy by generating heat through the regenerative resistor until the motor speed drops to a sufficiently low level or the motor stops rotating—that is, until the motor speed is below a preset first threshold. At this point, the control unit 202 then disconnects the regenerative resistor to prepare for the next motor start-up. This eliminates the need for additional relays, enabling dynamic braking of the servo drive even in the event of an inverter module drive failure. This improves the stability of dynamic braking, reduces hardware costs, and, by rapidly dissipating regenerative energy through the regenerative resistor, increases the dynamic braking torque, reduces the stopping distance and time for dynamic braking of the servo drive, and improves the efficiency of dynamic braking.

[0159] The specific value of the first threshold can be set by those skilled in the art according to the actual situation, and no specific restrictions are imposed here.

[0160] Understandably, the Stop 0 mode in a robot control system has the following characteristics: Immediate stop: The robot immediately stops all movement, regardless of its current speed and position; High priority: Typically used in emergencies, such as safety protection triggers or collision detection; Risk of impact: Due to the immediate stop, it may cause significant mechanical impact on the robot and load; Complex recovery: The robot needs to be reset and recalibrated after stopping to ensure a safe restart. Among these, stopping distance and stopping time are important parameters of the Stop 0 mode. For example, the stopping distance and stopping time of the first three axes of a six-axis industrial robot in Stop 0 mode are shown in Table 1 above. The shorter the stopping distance and stopping time in Stop 0 mode, the less likely a collision will occur when the robot stops, and the higher the safety of the robot control system.

[0161] However, the braking schemes in related technologies have relatively low dynamic braking torque at high motor speeds, resulting in longer stopping distances and times, thus failing to quickly reduce motor speed and leading to low efficiency in dynamic braking. Furthermore, these braking schemes cannot achieve dynamic braking in the event of inverter module drive failure or complete controller power failure, exhibiting poor stability and requiring additional relays, which increases hardware costs.

[0162] Therefore, the control device 200 for the servo driver provided by this invention does not use additional relays, but instead employs a regenerative resistor and a power supply module that can be turned off. During dynamic braking, by turning off the power supply module and the IGBTs in the inverter module, the diodes in the inverter module rectify the motor output current. Even when the inverter module cannot drive normally, such as in the case of a fault in the inverter module's drive circuit, a power outage in the inverter module's drive circuit, or a complete power outage of the controller, dynamic braking of the servo driver can still be achieved, improving the stability of dynamic braking. Furthermore, by replacing the motor winding resistor with a regenerative resistor, the regenerative energy during the motor deceleration process can be consumed more concentratedly and efficiently, increasing the dynamic braking torque, reducing the stopping distance and time of the servo driver during dynamic braking, and improving the efficiency of dynamic braking.

[0163] In practical applications, when the motor's back electromotive force (EMF) is higher than the DC bus capacitor voltage, the servo driver can be decelerated and braked by shutting down the servo driver's IPM (Intelligent Power Module). In this case, the deceleration energy is recovered by the DC bus capacitor, causing its voltage to rise. Once the DC bus capacitor voltage exceeds the motor's back EMF, the motor's braking torque becomes zero, and the motor can only stop due to friction.

[0164] The servo driver control device 200 provided in this embodiment of the invention can implement the steps of the servo driver control method in any of the above embodiments and achieve the same technical effect, which will not be described again here.

[0165] In one embodiment of the invention, another servo driver is also proposed. For example... Figure 9 As shown, Figure 9 A structural block diagram of a servo driver 300 provided in an embodiment of the present invention is shown. The servo driver 300 includes:

[0166] Memory 302, on which programs or instructions are stored;

[0167] The processor 304 executes the above-described program or instructions to implement the steps of the servo drive control method as described in any of the above embodiments.

[0168] The servo driver 300 provided in this embodiment includes a memory 302 and a processor 304. When the program or instructions in the memory 302 are executed by the processor 304, they implement the steps of the servo driver control method as described in any of the above embodiments. Therefore, the servo driver 300 has all the beneficial effects of the servo driver control method described in any of the above embodiments, which will not be repeated here.

[0169] Specifically, the memory 302 and the processor 304 can be connected via a bus or other means. The processor 304 may include one or more processing units, and the processor 304 may be a chip such as a central processing unit (CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), or a field-programmable gate array (FPGA).

[0170] In one embodiment of the invention, a controller is also provided. For example... Figure 10 As shown, Figure 10 A structural block diagram of a controller 400 provided in an embodiment of the present invention is shown. The controller 400 includes the servo driver 300 described in the above embodiments. Therefore, the controller 400 possesses all the technical effects of the servo driver 300 described in the above embodiments, and will not be repeated here.

[0171] In one embodiment of the present invention, an industrial robot is also proposed. For example... Figure 11 As shown, Figure 11A structural block diagram of an industrial robot 500 provided in an embodiment of the present invention is shown. The industrial robot 500 includes the controller 400 described in the above embodiments. Therefore, the industrial robot 500 possesses all the technical effects of the controller 400 described in the above embodiments, and will not be repeated here.

[0172] In one embodiment of the present invention, a readable storage medium is also provided. A program or instructions are stored thereon, which, when executed by a processor, implement the steps of the servo driver control method as described in any of the above embodiments.

[0173] The readable storage medium provided in this embodiment of the invention stores programs or instructions that, when executed by a processor, can implement the steps of the servo driver control method as described in any of the above embodiments. Therefore, this readable storage medium possesses all the beneficial effects of the servo driver control method in any of the above embodiments, which will not be elaborated further here.

[0174] Specifically, the aforementioned readable storage medium can include any medium capable of storing or transmitting information. Examples of readable storage media include electronic circuits, semiconductor memory devices, read-only memory (ROM), random access memory (RAM), compact disc read-only memory (CD-ROM), flash memory, erasable ROM (EROM), magnetic tape, floppy disk, optical disk, hard disk, fiber optic media, radio frequency (RF) links, optical data storage devices, etc. Code segments can be downloaded via computer networks such as the Internet and intranets.

[0175] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance, unless otherwise expressly specified and limited. The terms "connection," "installation," and "fixing," etc., should be interpreted broadly. For example, "connection" can mean a fixed connection, a detachable connection, or an integral connection; it can mean a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0176] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. 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.

[0177] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0178] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for a servo driver, characterized in that, The servo driver includes a power-offable power module, a regenerative resistor, a DC bus capacitor, an inverter module, and a motor. The power module is connected to the regenerative resistor, the DC bus capacitor, and the inverter module. The inverter module is also connected to the motor. The control method includes: Upon receiving a dynamic braking command, the power module is controlled to stop charging the DC bus capacitor. The inverter module is turned off so that the motor charges the DC bus capacitor through the inverter module; The regenerative resistor is controlled to be turned on until the speed of the motor is less than a first threshold, and then the regenerative resistor is controlled to be turned off.

2. The control method for the servo driver according to claim 1, characterized in that, The servo driver further includes a switching transistor connected to both the regenerative resistor and the power module. Controlling the regenerative resistor to turn on includes: The switching transistor is controlled to turn on, thereby turning on the regenerative resistor; The signal duty cycle of the switching transistor gradually increases from 0 to 100%.

3. The control method for the servo driver according to claim 2, characterized in that, Also includes: Calculate the electrical energy consumed by the regenerative resistor; The average power of the regenerative resistor is determined based on the consumed electrical energy. If the average power is greater than the second threshold, the signal duty cycle of the switching transistor is reduced.

4. The control method for the servo driver according to claim 3, characterized in that, The calculation of the electrical energy consumed by the regenerative resistor includes: The energy consumption of the regenerative resistor shall be calculated according to the following formula; E=(V1 2 ×t) / R; Where E is the electrical energy consumed, V1 is the nominal voltage of the DC bus capacitor, t is the conduction time of the switching transistor, and R is the nominal resistance of the regenerative resistor.

5. The control method for the servo driver according to claim 3, characterized in that, The calculation of the electrical energy consumed by the regenerative resistor includes: The energy consumption of the regenerative resistor shall be calculated according to the following formula; E=(V2 2 ×t) / R; Where E is the electrical energy consumed, V2 is the real-time voltage of the DC bus capacitor, t is the conduction time of the switching transistor, and R is the nominal resistance value of the regenerative resistor.

6. The control method for the servo driver according to claim 2, characterized in that, Also includes: Detect the phase current of the motor; When the phase current of the motor is greater than the maximum current of the motor, the signal duty cycle of the switching transistor is reduced.

7. The control method for the servo driver according to claim 6, characterized in that, The reduction of the signal duty cycle of the switching transistor includes: Reduce the signal duty cycle of the switching transistor using a closed-loop control algorithm; or... The signal duty cycle of the switching transistor is reduced according to a preset duty cycle adjustment strategy.

8. The control method for the servo drive according to any one of claims 1 to 7, characterized in that, Also includes: While ensuring that the line current of the motor is less than the peak current of the motor, the difference between the line current and the peak current of the motor is reduced.

9. The control method for the servo driver according to any one of claims 1 to 7, characterized in that, The control of the power module to stop charging the DC bus capacitor includes: If the power module includes an AC power supply and a fully controlled rectifier bridge, control the fully controlled rectifier bridge to shut down; If the power module is a switchable DC power supply, control the DC power supply to turn off; If the power module is a switchable battery, control the battery to turn off.

10. A control device for a servo driver, characterized in that, The servo driver includes a power-offable power module, a regenerative resistor, a DC bus capacitor, an inverter module, and a motor. The power module is connected to the regenerative resistor, the DC bus capacitor, and the inverter module, and the inverter module is also connected to the motor. The control device includes: The control unit is used to control the power module to stop charging the DC bus capacitor when a dynamic braking command is received. The control unit is also used to shut down the inverter module so that the motor can charge the DC bus capacitor through the inverter module; The control unit is also used to control the regenerative resistor to conduct until the speed of the motor is less than a first threshold, and then control the regenerative resistor to disconnect.

11. A servo driver, characterized in that, It includes a processor and a memory, the memory storing a program or instructions that can run on the processor, the program or instructions being executed by the processor to implement the steps of the control method of the servo drive as described in any one of claims 1 to 9.

12. A controller, characterized in that, include: The servo driver as described in claim 11.

13. An industrial robot, characterized in that, include: The controller as described in claim 12.

14. A readable storage medium, characterized in that, The readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the servo drive control method as described in any one of claims 1 to 9.

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