Current bias compensation control method and device, electronic equipment and readable storage medium

Abstract

The application provides a current bias compensation control method and device, electronic equipment and a readable storage medium, and relates to the technical field of servo control. The method comprises the following steps: acquiring an electric angle corresponding to each phase current in a zero current state in a three-phase current; determining a first temporary current bias value, a second temporary current bias value and a third temporary current bias value based on a first electric angle, a second electric angle and a third electric angle; determining a first corrected current bias value, a second corrected current bias value and a third corrected current bias value; and calculating a first corrected current value, a second corrected current value and a third corrected current value. In the technical scheme of the application, the current bias value of each phase current in the zero current state is determined based on the electric angle, the running time and the running temperature of a servo motor; and the corrected current value of each phase current is determined according to the real-time current value and the current bias value. This method is beneficial to eliminating the current sampling error caused by the current bias, and the current sampling is more accurate.

Description

Technical Field

[0001] This invention relates to the field of servo control technology, and more specifically, to a current bias compensation control method, apparatus, electronic device, and readable storage medium. Background Technology

[0002] In the field of servo control technology, accurate sampling of three-phase current is a core prerequisite for achieving high-performance field-oriented control (FOC), torque closed-loop control, and stable speed regulation of motors. Whether it is the precision transmission mechanism of an industrial automated production line, the spindle drive of a CNC machine tool, or the power control of robot joints, all rely on real-time and accurate three-phase current data. Through current loop calculations, appropriate control signals are generated to drive the servo motor to output stable torque and speed, thereby ensuring the operational accuracy and reliability of the equipment.

[0003] In related technologies, the three-phase current of a servo motor is sampled using a "direct detection-signal conversion" method. Specifically, the voltage drop signal corresponding to the current is obtained by a sampling resistor (such as a manganin shunt resistor) connected in series in the motor phase lines, or the phase line current is directly sensed using a Hall current sensor. The collected analog signal is then converted into a digital signal by an analog-to-digital converter (ADC). Finally, the digital signal is used as the "actual value of the three-phase current" and input to the servo controller for subsequent vector transformation, current loop PI (Proportional-Integral) adjustment, and other core control logic.

[0004] However, sampling the three-phase current of the servo motor using the "direct detection-signal conversion" method does not account for current sampling errors caused by current bias. Therefore, the current values ​​of each phase differ significantly from the actual values, affecting the accuracy of subsequent data processing results. Summary of the Invention

[0005] In order to solve or improve the technical problem of poor accuracy in sampling three-phase current in related technologies, one object of the present invention is to provide a current bias compensation control method.

[0006] Another object of the present invention is to provide a current bias compensation control device.

[0007] Another object of the present invention is to provide an electronic device.

[0008] Another object of the present invention is to provide a readable storage medium.

[0009] To achieve the above objectives, the first aspect of the present invention provides a current bias compensation control method applied to a servo control system. The servo control system includes a servo motor, an encoder, and a control module. The encoder is connected to the rotor of the servo motor and is used to convert the angular displacement of the rotor into the electrical angle of the servo motor. The control module is electrically connected to the encoder.

[0010] The current bias compensation control method includes: acquiring the electrical angle of the servo motor through an encoder; acquiring the electrical angle corresponding to each phase current in the three-phase current when it is in a zero-current state; wherein, the three-phase current includes U-phase current, V-phase current, and W-phase current, the electrical angle corresponding to the U-phase current in a zero-current state is the first electrical angle, the electrical angle corresponding to the V-phase current in a zero-current state is the second electrical angle, and the electrical angle corresponding to the W-phase current in a zero-current state is the third electrical angle; based on the first electrical angle, determining a first temporary current bias value for the U-phase current; based on the second electrical angle, determining a second temporary current bias value for the V-phase current; based on the third electrical angle, determining a third temporary current bias value for the W-phase current; based on the first temporary current bias value... Based on the set values, servo motor running time, and operating temperature, determine the first corrected current bias value for the U-phase current; based on the second temporary current bias value, running time, and operating temperature, determine the second corrected current bias value for the V-phase current; based on the third temporary current bias value, running time, and operating temperature, determine the third corrected current bias value for the W-phase current; based on the first real-time current value and the first corrected current bias value of the U-phase current, calculate the first corrected current value of the U-phase current; based on the second real-time current value and the second corrected current bias value of the V-phase current, calculate the second corrected current value of the V-phase current; based on the third real-time current value and the third corrected current bias value of the W-phase current, calculate the third corrected current value of the W-phase current.

[0011] This invention aims to provide a current bias compensation control method. Based on the electrical angle, running time, and operating temperature of the servo motor, it determines the current bias value of each phase current in the zero-current state. Then, it determines the corrected current value for each phase current based on the real-time current value and the current bias value. This design can largely eliminate the current sampling error caused by current bias, making current sampling more accurate and thus improving the accuracy of subsequent data processing results.

[0012] It should be noted that the current bias value can be updated and corrected in real time based on the running time and operating temperature of the servo motor. Compensating for the current bias value during the operation of the servo motor helps to ensure the accuracy of current sampling.

[0013] In some technical solutions, optionally, a first corrected current bias value for the U-phase current is determined based on a first temporary current bias value, the running time of the servo motor, and the running temperature; a second corrected current bias value for the V-phase current is determined based on a second temporary current bias value, the running time, and the running temperature; and a third corrected current bias value for the W-phase current is determined based on a third temporary current bias value, the running time, and the running temperature. This includes: obtaining the power-on time node of the servo motor and determining the running time based on the power-on time node; obtaining the initial running temperature and current running temperature of the servo motor through a temperature sensor and determining the temperature rise value based on the initial running temperature and current running temperature; determining the first corrected current bias value based on the first temporary current bias value, the running time, and the temperature rise value; determining the second corrected current bias value based on the second temporary current bias value, the running time, and the temperature rise value; and determining the third corrected current bias value based on the third temporary current bias value, the running time, and the temperature rise value.

[0014] In this technical solution, the temporary current bias value is adjusted as the running time changes, and the temporary current bias value is also adjusted as the operating temperature changes, in order to obtain a corrected current bias value. The current bias value can be updated and corrected in real time based on the running time and operating temperature of the servo motor. Compensating for the current bias value during the operation of the servo motor helps to ensure the accuracy of current sampling.

[0015] In some technical solutions, optionally, a first corrected current bias value is determined based on a first temporary current bias value, operating time, and temperature rise value; a second corrected current bias value is determined based on a second temporary current bias value, operating time, and temperature rise value; and a third corrected current bias value is determined based on a third temporary current bias value, operating time, and temperature rise value. This includes: pre-establishing a mapping table showing the correspondence between operating time, temperature rise value, and current bias adjustment coefficient; determining the current bias adjustment coefficient based on the mapping table and the operating time and temperature rise value; calculating the first corrected current bias value based on the first temporary current bias value and the current bias adjustment coefficient; calculating the second corrected current bias value based on the second temporary current bias value and the current bias adjustment coefficient; and calculating the third corrected current bias value based on the third temporary current bias value and the current bias adjustment coefficient.

[0016] In this technical solution, during the operation of the servo motor, the current bias adjustment coefficient is continuously adjusted based on the mapping table, the running time, and the temperature rise value. This allows for the calculation of a corrected current bias value using both the temporary current bias value and the current bias adjustment coefficient. This design simplifies data processing and improves the accuracy of current sampling.

[0017] In some technical solutions, optionally, in the mapping table, for every 1 hour increase in running time, the current bias adjustment coefficient increases by 0.02 to 0.05; for every 5°C increase in temperature rise, the current bias adjustment coefficient increases by 0.02 to 0.05.

[0018] In this technical solution, by limiting the amount of change in the current bias adjustment coefficient each time, the amount of change in each increase is avoided to be too large or too small, which helps to ensure the accuracy of the corrected current bias value and thus improve the accuracy of current sampling.

[0019] In some technical solutions, optionally, the first corrected current bias value is equal to the product of the first temporary current bias value and the current bias adjustment coefficient; the second corrected current bias value is equal to the product of the second temporary current bias value and the current bias adjustment coefficient; and the third corrected current bias value is equal to the product of the third temporary current bias value and the current bias adjustment coefficient.

[0020] In this technical solution, the first temporary current bias value is calculated by multiplying it by the current bias adjustment coefficient; the second temporary current bias value is calculated by multiplying it by the current bias adjustment coefficient; and the third temporary current bias value is calculated by multiplying it by the current bias adjustment coefficient. This design method simplifies data processing and helps improve the accuracy of current sampling.

[0021] In some technical solutions, optionally, a first temporary current bias value for the U-phase current is determined based on a first electrical angle; a second temporary current bias value for the V-phase current is determined based on a second electrical angle; and a third temporary current bias value for the W-phase current is determined based on a third electrical angle. This includes: when the servo motor is at the first electrical angle, acquiring a first sampled current value of the U-phase current and using the first sampled current value as the first temporary current bias value; when the servo motor is at the second electrical angle, acquiring a second sampled current value of the V-phase current and using the second sampled current value as the second temporary current bias value; and when the servo motor is at the third electrical angle, acquiring a third sampled current value of the W-phase current and using the third sampled current value as the third temporary current bias value.

[0022] In this technical solution, a temporary current bias value is determined so that a corrected current bias value can be determined in subsequent steps based on the temporary current bias value, the servo motor's operating time, and its operating temperature. The current bias value can be updated and corrected in real time based on the servo motor's operating time and operating temperature to ensure more accurate current sampling.

[0023] In some technical solutions, optionally, the first corrected current value is equal to the difference between the first real-time current value and the first corrected current bias value; the second corrected current value is equal to the difference between the second real-time current value and the second corrected current bias value; and the third corrected current value is equal to the difference between the third real-time current value and the third corrected current bias value.

[0024] In this technical solution, the first corrected current value of phase U is calculated by subtracting the first real-time current value and the first corrected current bias value; the second corrected current value of phase V is calculated by subtracting the second real-time current value and the second corrected current bias value; and the third corrected current value of phase W is calculated by subtracting the third real-time current value and the third corrected current bias value. This design method simplifies data processing and helps improve the accuracy of current sampling.

[0025] A second aspect of the present invention provides a current bias compensation control device, comprising: an electrical angle acquisition unit for acquiring the electrical angle of a servo motor via an encoder; an initial electrical angle acquisition unit for acquiring the electrical angle corresponding to each phase current in a zero-current state among the three-phase currents; wherein the three-phase currents include a U-phase current, a V-phase current, and a W-phase current, the electrical angle corresponding to the U-phase current in a zero-current state is a first electrical angle, the electrical angle corresponding to the V-phase current in a zero-current state is a second electrical angle, and the electrical angle corresponding to the W-phase current in a zero-current state is a third electrical angle; and a temporary current bias value determination unit for determining a first temporary current bias value for the U-phase current based on the first electrical angle; determining a second temporary current bias value for the V-phase current based on the second electrical angle; and determining a third temporary current bias value for the W-phase current based on the third electrical angle. The system includes: a correction current bias value determination unit, used to determine a first correction current bias value for the U-phase current based on a first temporary current bias value, the running time of the servo motor, and the running temperature; a second correction current bias value for the V-phase current based on a second temporary current bias value, the running time, and the running temperature; and a third correction current bias value for the W-phase current based on a third temporary current bias value, the running time, and the running temperature; and a correction current value calculation unit, used to calculate a first correction current value for the U-phase current based on a first real-time current value and a first correction current bias value; a second correction current value for the V-phase current based on a second real-time current value and a second correction current bias value; and a third correction current value for the W-phase current based on a third real-time current value and a third correction current bias value.

[0026] This invention aims to provide a current bias compensation control device that determines the current bias value of each phase current in a zero-current state based on the electrical angle, running time, and operating temperature of a servo motor; and determines the corrected current value of each phase current based on the real-time current value and the current bias value. This design can largely eliminate the current sampling error caused by current bias, making current sampling more accurate and thus improving the accuracy of subsequent data processing results.

[0027] It should be noted that the current bias value can be updated and corrected in real time based on the servo motor's running time and operating temperature. Compensating for the current bias value during servo motor operation helps ensure the accuracy of current sampling.

[0028] A third aspect of the present invention provides an electronic device, comprising: a memory and a processor, wherein the memory stores a program or instructions executable on the processor, and the processor, when executing the program or instructions, implements the steps of the current bias compensation control method in any of the above-described technical solutions. The electronic device possesses the beneficial effects of any of the above-described technical solutions, which will not be elaborated further here.

[0029] A fourth aspect of the present invention provides a readable storage medium storing a program or instructions, which, when executed by a processor, implement the steps of the current bias compensation control method in any of the above-described technical solutions. The readable storage medium possesses the beneficial effects of any of the above-described technical solutions, which will not be elaborated further here.

[0030] Additional aspects and advantages of the technical solutions of the present invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0031] Figure 1 A structural block diagram of a servo control system according to an embodiment of the present invention is shown;

[0032] Figure 2 A structural block diagram of a servo control system according to another embodiment of the present invention is shown;

[0033] Figure 3 A flowchart of a current bias compensation control method according to an embodiment of the present invention is shown;

[0034] Figure 4 A flowchart of a current bias compensation control method according to another embodiment of the present invention is shown;

[0035] Figure 5 A flowchart of a current bias compensation control method according to another embodiment of the present invention is shown;

[0036] Figure 6A flowchart of a current bias compensation control method according to another embodiment of the present invention is shown;

[0037] Figure 7 A structural block diagram of a current bias compensation control device according to an embodiment of the present invention is shown;

[0038] Figure 8 A structural block diagram of an electronic device according to an embodiment of the present invention is shown.

[0039] in, Figures 1 to 8 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0040] 100: Servo control system; 110: Servo motor; 111: Rotor; 120: Encoder; 130: Control module; 140: Temperature sensor; 150: Timer; 300: Current bias compensation control device; 310: Electrical angle acquisition unit; 320: Initial electrical angle acquisition unit; 330: Temporary current bias value determination unit; 340: Corrected current bias value determination unit; 350: Corrected current value calculation unit; 400: Electronic equipment; 410: Memory; 420: Processor. Detailed Implementation

[0041] To better understand the above-described objectives, features, and advantages of the embodiments of the present invention, the embodiments of 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 and features described in these embodiments can be combined with each other.

[0042] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, embodiments of the invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0043] In the field of servo control technology, accurate sampling of three-phase current is a core prerequisite for achieving high-performance field-oriented control (FOC), torque closed-loop control, and stable speed regulation of motors. Whether it is the precision transmission mechanism of an industrial automated production line, the spindle drive of a CNC machine tool, or the power control of robot joints, all rely on real-time and accurate three-phase current data. Through current loop calculations, appropriate control signals are generated to drive the servo motor to output stable torque and speed, thereby ensuring the operational accuracy and reliability of the equipment.

[0044] In related technologies, the three-phase current of a servo motor is sampled using a "direct detection-signal conversion" method. Specifically, the voltage drop signal corresponding to the current is obtained by a sampling resistor (such as a manganin shunt resistor) connected in series in the motor phase lines, or the phase line current is directly sensed using a Hall current sensor. The collected analog signal is then converted into a digital signal by an analog-to-digital converter (ADC). Finally, the digital signal is used as the "actual value of the three-phase current" and input to the servo controller for subsequent vector transformation, current loop PI (Proportional-Integral) adjustment, and other core control logic.

[0045] However, sampling the three-phase current of the servo motor using the "direct detection-signal conversion" method does not account for current sampling errors caused by current bias. Therefore, the current values ​​of each phase differ significantly from the actual values, affecting the accuracy of subsequent data processing results.

[0046] It should be noted that in the zero-current state (when no current flows through the motor phase lines), the hardware characteristics of the sampling circuit itself will cause the ADC (Analog-to-Digital Converter) to still output a non-zero digital signal, i.e., a "current bias signal." The sources of this "current bias signal" include: the zero-drift characteristic of the sampling resistor (even without current flowing, the resistor's temperature coefficient will cause a small voltage output), the input offset voltage of the operational amplifier in the signal amplification circuit, and the zero-point offset error of the ADC, etc.

[0047] This invention aims to provide a current bias compensation control method, device, electronic device, and readable storage medium. Based on the electrical angle, running time, and operating temperature of a servo motor, it determines the current bias value of each phase current in a zero-current state; and determines the corrected current value of each phase current based on the real-time current value and the current bias value. This design can largely eliminate current sampling errors caused by current bias, making current sampling more accurate and thus improving the accuracy of subsequent data processing results.

[0048] It should be noted that subsequent data processing steps include, but are not limited to, vector transformation and PI regulation of the current loop.

[0049] In related technologies, when sampling the current of each phase in a three-phase current system, the correct vector current (corrected current value) is determined by subtracting the real-time current value from the current bias value. However, considering factors such as the resistance of the sampling resistor changing at different temperatures, the current bias value is not actually a constant. Setting the current bias value to a constant value makes it impossible to compensate for the current bias value during servo motor operation, affecting the accuracy of current sampling.

[0050] In the technical solution defined by this invention, the current bias value can be updated and corrected in real time based on the running time and operating temperature of the servo motor. Compensating for the current bias value during the operation of the servo motor helps to ensure the accuracy of current sampling.

[0051] The following reference Figures 1 to 8 This invention describes current bias compensation control methods, apparatus, electronic devices, and readable storage media provided according to some embodiments of the present invention.

[0052] In one embodiment of the present invention, such as Figure 1 As shown, the servo control system 100 includes a servo motor 110, an encoder 120, and a control module 130. The encoder 120 is connected to the rotor 111 of the servo motor 110, and the encoder 120 is used to convert the angular displacement of the rotor 111 into the electrical angle of the servo motor 110. The control module 130 is electrically connected to the encoder 120.

[0053] The servo motor 110 is an electric motor capable of precisely controlling position, speed, and acceleration. The encoder 120 is a device that converts rotary (angular) or linear displacement into a series of electrical signals. The control module 130 typically refers to an MCU (Microcontroller Unit Module).

[0054] The control module 130 controls the encoder 120 to acquire the angular displacement of the rotor 111 and converts the angular displacement into a pulse signal. Based on the first calculation formula, the electrical angle of the servo motor 110 is calculated according to the pulse signal, the number of encoder lines of the encoder 120 and the number of pole pairs of the servo motor 110.

[0055] The first calculation formula is: Electrical angle of servo motor 110 = number of pulses × (360° / (number of lines × number of pole pairs)).

[0056] Optionally, the number of pulses is determined based on the pulse signal. The number of pulses refers to the total number of pulses output by the encoder 120 from the "electrical angle calculation reference point" (such as the zero position of the encoder 120 Z phase, the driver power-on initialization point) to the current time (or the amount of pulse change within a certain period). The number of lines in the encoder 120 refers to the number of etched lines on the code disk of the encoder 120. The number of pole pairs in the servo motor 110 refers to the number of N and S pole pairs of the permanent magnets on the rotor 111. Here, "N" stands for North Pole, and "S" stands for South Pole.

[0057] It should be noted that when encoder 120 is an incremental encoder, "Z phase" stands for ZeroPhase, which represents the zero-position reference signal channel output by encoder 120.

[0058] In some embodiments, optionally, such as Figure 2 As shown, the servo control system 100 also includes a temperature sensor 140. The temperature sensor 140 is located on the servo motor 110 and is used to acquire the operating temperature of the servo motor 110 in real time. The temperature sensor 140 is electrically connected to the control module 130. The control module 130 acquires the operating temperature of the servo motor 110 in real time through the temperature sensor 140.

[0059] In some embodiments, optionally, such as Figure 2 As shown, the servo control system 100 also includes a timer 150. The timer 150 is located on the servo motor 110 and is used to acquire the power-on time and running time of the servo motor 110. The timer 150 is electrically connected to the control module 130. The control module 130 acquires the power-on time and running time of the servo motor 110 through the timer 150.

[0060] In one embodiment of the present invention, the current bias compensation control method is applied to the servo control system 100.

[0061] like Figure 3 As shown, the current bias compensation control method includes:

[0062] S202 obtains the electrical angle of the servo motor through an encoder.

[0063] The electrical angle is a virtual angular parameter that describes the electromagnetic phase relationship between the stator winding and the rotor magnetic field in a servo motor. Its core function is to provide an "electromagnetic cycle reference" for field-oriented control (FOC), current bias compensation, and precise torque adjustment.

[0064] S204, obtain the electrical angle corresponding to each phase current in the three-phase current when it is in the zero-current state; wherein, the three-phase current includes U-phase current, V-phase current and W-phase current, the electrical angle corresponding to the U-phase current when it is in the zero-current state is the first electrical angle, the electrical angle corresponding to the V-phase current when it is in the zero-current state is the second electrical angle, and the electrical angle corresponding to the W-phase current when it is in the zero-current state is the third electrical angle.

[0065] It should be noted that the zero-current state refers to the situation where no current flows through the motor's phase lines. "U phase" refers to Phase U; "V phase" refers to Phase V; and "W phase" refers to Phase W.

[0066] Obtain the first electrical angle corresponding to the U-phase current in the zero-current state; obtain the second electrical angle corresponding to the V-phase current in the zero-current state; obtain the third electrical angle corresponding to the W-phase current in the zero-current state.

[0067] Taking the range of electrical angles of a servo motor from 0° to 360° as an example, the first electrical angle is 0° and 180°; the second electrical angle is 60° and 240°; and the third electrical angle is 120° and 300°.

[0068] It should be noted that if the electrical angle is not within the range of 0° to 360°, the current electrical angle can be equivalent to an electrical angle within the range of 0° to 360°. For example, if the electrical angle is 370°, it can be equivalent to an electrical angle of 10°.

[0069] The purpose of this step is to obtain the electrical angle corresponding to each phase current in the zero-current state, so that the temporary current bias value of each phase current can be determined based on the electrical angle in subsequent steps.

[0070] S206, based on the first electrical angle, determine the first temporary current bias value of the U-phase current; based on the second electrical angle, determine the second temporary current bias value of the V-phase current; based on the third electrical angle, determine the third temporary current bias value of the W-phase current.

[0071] When the servo motor is at the first electrical angle, the first sampled current value of the U-phase current is obtained through an analog-to-digital converter (ADC), and the first sampled current value is used as the first temporary current bias value.

[0072] When the servo motor is at the second electrical angle, the second sampled current value of the V-phase current is obtained through an analog-to-digital converter, and the second sampled current value is used as the second temporary current bias value.

[0073] When the servo motor is at the third electrical angle, the third sampled current value of the W phase current is obtained through an analog-to-digital converter, and the third sampled current value is used as the third temporary current bias value.

[0074] S208: Based on the first temporary current bias value, the running time of the servo motor, and the running temperature, determine the first corrected current bias value of the U-phase current; based on the second temporary current bias value, the running time, and the running temperature, determine the second corrected current bias value of the V-phase current; based on the third temporary current bias value, the running time, and the running temperature, determine the third corrected current bias value of the W-phase current.

[0075] The current bias value can be updated and corrected in real time based on the running time and operating temperature of the servo motor. Compensating for the current bias value during the operation of the servo motor helps to ensure the accuracy of current sampling.

[0076] S210, based on the first real-time current value and the first corrected current bias value of the U-phase current, calculate the first corrected current value of the U-phase current; based on the second real-time current value and the second corrected current bias value of the V-phase current, calculate the second corrected current value of the V-phase current; based on the third real-time current value and the third corrected current bias value of the W-phase current, calculate the third corrected current value of the W-phase current.

[0077] The first corrected current value of phase U is obtained by subtracting the first real-time current value and the first corrected current bias value; the second corrected current value of phase V is obtained by subtracting the second real-time current value and the second corrected current bias value; and the third corrected current value of phase W is obtained by subtracting the third real-time current value and the third corrected current bias value.

[0078] This invention aims to provide a current bias compensation control method. Based on the electrical angle, running time, and operating temperature of the servo motor, it determines the current bias value of each phase current in the zero-current state. Then, it determines the corrected current value for each phase current based on the real-time current value and the current bias value. This design can largely eliminate the current sampling error caused by current bias, making current sampling more accurate and thus improving the accuracy of subsequent data processing results.

[0079] It should be noted that the current bias value can be updated and corrected in real time based on the running time and operating temperature of the servo motor. Compensating for the current bias value during the operation of the servo motor helps to ensure the accuracy of current sampling.

[0080] In some embodiments, optionally, such as Figure 4As shown, S208 (determining a first corrected current bias value for the U-phase current based on a first temporary current bias value, the servo motor's running time, and operating temperature; determining a second corrected current bias value for the V-phase current based on a second temporary current bias value, running time, and operating temperature; and determining a third corrected current bias value for the W-phase current based on a third temporary current bias value, running time, and operating temperature) includes:

[0081] S2081: Obtain the power-on time node of the servo motor and determine the running time based on the power-on time node; obtain the initial running temperature and current running temperature of the servo motor through the temperature sensor and determine the temperature rise value of the running temperature based on the initial running temperature and current running temperature.

[0082] The servo motor's power-on time and current time are obtained using a timer, and the servo motor's running time is determined based on these two times. The current bias value is adjusted as the running time changes.

[0083] The initial and current operating temperatures of the servo motor are obtained using a temperature sensor. Based on these temperatures, the temperature rise is determined. This temperature rise reflects the magnitude of temperature change. The current bias is adjusted as the operating temperature changes.

[0084] S2082, based on the first temporary current bias value, the operating time, and the temperature rise value, determine the first corrected current bias value; based on the second temporary current bias value, the operating time, and the temperature rise value, determine the second corrected current bias value; based on the third temporary current bias value, the operating time, and the temperature rise value, determine the third corrected current bias value.

[0085] The temporary current bias value is adjusted as the running time and operating temperature change to obtain a corrected current bias value. The current bias value can be updated and corrected in real time based on the servo motor's running time and operating temperature. Compensating for the current bias value during servo motor operation helps ensure the accuracy of current sampling.

[0086] In some embodiments, optionally, such as Figure 5 As shown, S2082 (determining a first corrected current bias value based on a first temporary current bias value, operating time, and temperature rise value; determining a second corrected current bias value based on a second temporary current bias value, operating time, and temperature rise value; determining a third corrected current bias value based on a third temporary current bias value, operating time, and temperature rise value) includes:

[0087] S2083, pre-establish a mapping table showing the correspondence between running time, temperature rise value, and current bias adjustment coefficient.

[0088] Based on historical databases, a mapping table is pre-established to show the correspondence between running time, temperature rise, and current bias adjustment coefficient.

[0089] The purpose of this step is to pre-establish a mapping table so that the current bias adjustment coefficient can be determined by looking up the table in subsequent steps.

[0090] S2084, based on the mapping table, determines the current bias adjustment coefficient according to the running time and temperature rise value.

[0091] Given a fixed operating time and temperature rise, determining the current bias adjustment coefficient by looking up a table simplifies data processing and improves the efficiency of current sampling.

[0092] S2085, calculate the first corrected current bias value based on the first temporary current bias value and the current bias adjustment coefficient.

[0093] The first corrected current bias value is calculated by multiplying the first temporary current bias value and the current bias adjustment coefficient.

[0094] S2086, Calculate the second corrected current bias value based on the second temporary current bias value and the current bias adjustment coefficient.

[0095] The second temporary current bias value is calculated by multiplying the current bias adjustment coefficient by the second temporary current bias value.

[0096] S2087, calculate the third corrected current bias value based on the third temporary current bias value and the current bias adjustment coefficient.

[0097] The third corrected current bias value is calculated by multiplying the third temporary current bias value and the current bias adjustment coefficient.

[0098] During servo motor operation, the current bias adjustment coefficient is continuously adjusted based on the mapping table, the running time, and temperature rise, so that the corrected current bias value can be calculated based on the temporary current bias value and the current bias adjustment coefficient. This design method simplifies data processing and improves the accuracy of current sampling.

[0099] In some embodiments, optionally, in the mapping table, the current bias adjustment factor increases by 0.02 to 0.05 for every 1 hour increase in running time; and the current bias adjustment factor increases by 0.02 to 0.05 for every 5°C increase in temperature rise.

[0100] As the running time increases, the current bias adjustment coefficient is increased; similarly, as the temperature rise increases, the current bias adjustment coefficient is also increased. The current bias value can be updated and corrected in real time based on the servo motor's running time and operating temperature. Compensating for the current bias value during servo motor operation helps ensure the accuracy of current sampling.

[0101] By limiting the amount of change in the current bias adjustment coefficient each time, and avoiding excessively large or small changes each time, it is beneficial to ensure the accuracy of the corrected current bias value, thereby improving the accuracy of current sampling.

[0102] In some embodiments, optionally, the first corrected current bias value is equal to the product of the first temporary current bias value and the current bias adjustment coefficient; the second corrected current bias value is equal to the product of the second temporary current bias value and the current bias adjustment coefficient; and the third corrected current bias value is equal to the product of the third temporary current bias value and the current bias adjustment coefficient.

[0103] The first corrected current bias value is calculated by multiplying the first temporary current bias value and the current bias adjustment coefficient; the second corrected current bias value is calculated by multiplying the second temporary current bias value and the current bias adjustment coefficient; and the third corrected current bias value is calculated by multiplying the third temporary current bias value and the current bias adjustment coefficient. This design method simplifies data processing and helps improve the accuracy of current sampling.

[0104] In some embodiments, optionally, such as Figure 6 As shown, S206 (determining the first temporary current bias value of the U-phase current based on the first electrical angle; determining the second temporary current bias value of the V-phase current based on the second electrical angle; determining the third temporary current bias value of the W-phase current based on the third electrical angle) includes:

[0105] S2062, when the servo motor is at the first electrical angle, acquire the first sampled current value of the U-phase current and use the first sampled current value as the first temporary current bias value.

[0106] When the servo motor is at the first electrical angle, the first sampled current value of the U-phase current is obtained through an analog-to-digital converter, and the first sampled current value is used as the first temporary current bias value.

[0107] Taking the range of electrical angle of a servo motor from 0° to 360° as an example, the first electrical angle is 0° and 180°.

[0108] S2064: When the servo motor is at the second electrical angle, the second sampled current value of the V phase current is obtained, and the second sampled current value is used as the second temporary current bias value.

[0109] When the servo motor is at the second electrical angle, the second sampled current value of the V-phase current is obtained through an analog-to-digital converter, and the second sampled current value is used as the second temporary current bias value.

[0110] Taking the range of electrical angle of a servo motor from 0° to 360° as an example, the second electrical angle is 60° and 240°.

[0111] S2066: When the servo motor is at the third electrical angle, obtain the third sampled current value of the W phase current and use the third sampled current value as the third temporary current bias value.

[0112] When the servo motor is at the third electrical angle, the third sampled current value of the W phase current is obtained through an analog-to-digital converter, and the third sampled current value is used as the third temporary current bias value.

[0113] Taking the range of electrical angle of a servo motor from 0° to 360° as an example, the third electrical angle is 120° and 300°.

[0114] In the zero-current state (when no current flows through the motor phase lines), the hardware characteristics of the sampling circuit itself will cause the ADC (Analog-to-Digital Converter) to still output a non-zero digital signal, namely the "current bias signal". The "current bias signal" is represented as a temporary current bias value in the above steps.

[0115] By determining a temporary current bias value, a corrected current bias value can be determined in subsequent steps based on this temporary current bias value, the servo motor's operating time, and operating temperature. The current bias value can be updated and corrected in real time based on the servo motor's operating time and temperature to ensure more accurate current sampling.

[0116] In some embodiments, optionally, the first corrected current value is equal to the difference between the first real-time current value and the first corrected current bias value; the second corrected current value is equal to the difference between the second real-time current value and the second corrected current bias value; and the third corrected current value is equal to the difference between the third real-time current value and the third corrected current bias value.

[0117] The first corrected current value of phase U is calculated by subtracting the first real-time current value and the first corrected current bias value; the second corrected current value of phase V is calculated by subtracting the second real-time current value and the second corrected current bias value; and the third corrected current value of phase W is calculated by subtracting the third real-time current value and the third corrected current bias value. This design method simplifies data processing and improves the accuracy of current sampling.

[0118] In some embodiments, the current sampling timing relationship is optionally shown in the following table:

[0119]

[0120] In one embodiment of the present invention, the current bias compensation control device 300 is applied to the servo control system 100.

[0121] like Figure 7 As shown, the current bias compensation control device 300 includes an electrical angle acquisition unit 310, an initial electrical angle acquisition unit 320, a temporary current bias value determination unit 330, a corrected current bias value determination unit 340, and a corrected current value calculation unit 350.

[0122] The electrical angle acquisition unit 310 is used to acquire the electrical angle of the servo motor 110 through the encoder 120.

[0123] The electrical angle is a virtual angular parameter that describes the electromagnetic phase relationship between the stator winding and the rotor magnetic field in the servo motor 110. Its core function is to provide an "electromagnetic cycle reference" for field-oriented control (FOC), current bias compensation, and precise torque adjustment.

[0124] The initial electrical angle acquisition unit 320 is used to acquire the electrical angle corresponding to each phase current in the three-phase current when it is in the zero-current state; wherein, the three-phase current includes U-phase current, V-phase current and W-phase current, the electrical angle corresponding to the U-phase current when it is in the zero-current state is the first electrical angle, the electrical angle corresponding to the V-phase current when it is in the zero-current state is the second electrical angle, and the electrical angle corresponding to the W-phase current when it is in the zero-current state is the third electrical angle.

[0125] It should be noted that the zero-current state refers to the situation where no current flows through the motor's phase lines. "U phase" refers to Phase U; "V phase" refers to Phase V; and "W phase" refers to Phase W.

[0126] Obtain the first electrical angle corresponding to the U-phase current in the zero-current state; obtain the second electrical angle corresponding to the V-phase current in the zero-current state; obtain the third electrical angle corresponding to the W-phase current in the zero-current state.

[0127] Taking the range of electrical angle values ​​of servo motor 110 from 0° to 360° as an example, the first electrical angle is 0° and 180°; the second electrical angle is 60° and 240°; and the third electrical angle is 120° and 300°.

[0128] It should be noted that if the electrical angle is not within the range of 0° to 360°, the current electrical angle can be equivalent to an electrical angle within the range of 0° to 360°. For example, if the electrical angle is 370°, it can be equivalent to an electrical angle of 10°.

[0129] The temporary current bias value determination unit 330 is used to determine the first temporary current bias value of the U-phase current based on the first electrical angle; to determine the second temporary current bias value of the V-phase current based on the second electrical angle; and to determine the third temporary current bias value of the W-phase current based on the third electrical angle.

[0130] When the servo motor 110 is at the first electrical angle, the first sampled current value of the U-phase current is obtained by the analog-to-digital converter (ADC), and the first sampled current value is used as the first temporary current bias value.

[0131] When the servo motor 110 is at the second electrical angle, the second sampled current value of the V phase current is obtained through the analog-to-digital converter, and the second sampled current value is used as the second temporary current bias value.

[0132] When the servo motor 110 is at the third electrical angle, the third sampled current value of the W phase current is obtained through the analog-to-digital converter, and the third sampled current value is used as the third temporary current bias value.

[0133] The corrected current bias value determination unit 340 is used to determine a first corrected current bias value for the U-phase current based on a first temporary current bias value, the running time of the servo motor 110, and the running temperature; to determine a second corrected current bias value for the V-phase current based on a second temporary current bias value, the running time, and the running temperature; and to determine a third corrected current bias value for the W-phase current based on a third temporary current bias value, the running time, and the running temperature.

[0134] The current bias value can be updated and corrected in real time based on the running time and operating temperature of the servo motor 110. Compensating for the current bias value during the operation of the servo motor 110 helps to ensure the accuracy of current sampling.

[0135] The corrected current value calculation unit 350 is used to calculate the first corrected current value of the U-phase current based on the first real-time current value and the first corrected current bias value of the U-phase current; to calculate the second corrected current value of the V-phase current based on the second real-time current value and the second corrected current bias value of the V-phase current; and to calculate the third corrected current value of the W-phase current based on the third real-time current value and the third corrected current bias value of the W-phase current.

[0136] The first corrected current value of phase U is obtained by subtracting the first real-time current value and the first corrected current bias value; the second corrected current value of phase V is obtained by subtracting the second real-time current value and the second corrected current bias value; and the third corrected current value of phase W is obtained by subtracting the third real-time current value and the third corrected current bias value.

[0137] This invention aims to provide a current bias compensation control device 300, which determines the current bias value of each phase current in the three-phase current when it is in a zero-current state based on the electrical angle, running time, and operating temperature of the servo motor 110; and determines the corrected current value of each phase current based on the real-time current value and the current bias value. This design can largely eliminate the current sampling error caused by current bias, making current sampling more accurate and thus improving the accuracy of subsequent data processing results.

[0138] It should be noted that the current bias value can be updated and corrected in real time based on the running time and operating temperature of the servo motor 110. Compensating for the current bias value during the operation of the servo motor 110 helps to ensure the accuracy of current sampling.

[0139] In one embodiment of the present invention, such as Figure 8 As shown, the electronic device 400 includes a memory 410 and a processor 420. The memory 410 stores programs or instructions that can be executed on the processor 420. When the processor 420 executes the programs or instructions, it implements the steps of the current bias compensation control method in any of the above embodiments. The electronic device 400 has the beneficial effects of any of the above embodiments, which will not be elaborated further here.

[0140] In one embodiment of the present invention, the readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the current bias compensation control method in any of the above embodiments. The readable storage medium possesses the beneficial effects of any of the above embodiments, which will not be elaborated further here.

[0141] In this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be 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.

[0142] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0143] 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.

[0144] The above are merely preferred embodiments of the present invention and are not intended to limit the present 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 current bias compensation control method, characterized in that, This is applied to a servo control system, which includes a servo motor, an encoder, and a control module. The encoder is connected to the rotor of the servo motor and is used to convert the angular displacement of the rotor into the electrical angle of the servo motor. The control module is electrically connected to the encoder. The current bias compensation control method includes: The electrical angle of the servo motor is obtained through the encoder; The electrical angle corresponding to each phase current in the three-phase current when it is in a zero-current state is obtained; wherein, the three-phase current includes U-phase current, V-phase current and W-phase current, the electrical angle corresponding to the U-phase current when it is in a zero-current state is the first electrical angle, the electrical angle corresponding to the V-phase current when it is in a zero-current state is the second electrical angle, and the electrical angle corresponding to the W-phase current when it is in a zero-current state is the third electrical angle. Based on the first electrical angle, a first temporary current bias value for the U-phase current is determined; based on the second electrical angle, a second temporary current bias value for the V-phase current is determined; based on the third electrical angle, a third temporary current bias value for the W-phase current is determined. Based on the first temporary current bias value, the running time of the servo motor, and the running temperature, a first corrected current bias value for the U-phase current is determined; based on the second temporary current bias value, the running time, and the running temperature, a second corrected current bias value for the V-phase current is determined; based on the third temporary current bias value, the running time, and the running temperature, a third corrected current bias value for the W-phase current is determined. Based on the first real-time current value and the first corrected current bias value of the U-phase current, calculate the first corrected current value of the U-phase current; based on the second real-time current value and the second corrected current bias value of the V-phase current, calculate the second corrected current value of the V-phase current; based on the third real-time current value and the third corrected current bias value of the W-phase current, calculate the third corrected current value of the W-phase current.

2. The current bias compensation control method according to claim 1, characterized in that, The first corrected current bias value of the U-phase current is determined based on the first temporary current bias value, the running time of the servo motor, and the running temperature. Based on the second temporary current bias value, the operating time, and the operating temperature, a second corrected current bias value for the V-phase current is determined; Based on the third temporary current bias value, the operating time, and the operating temperature, the third corrected current bias value of the W-phase current is determined, including: The power-on time of the servo motor is obtained, and the running time is determined based on the power-on time. The initial running temperature and the current running temperature of the servo motor are obtained through a temperature sensor, and the temperature rise value of the running temperature is determined based on the initial running temperature and the current running temperature. Based on the first temporary current bias value, the operating time, and the temperature rise value, a first corrected current bias value is determined; based on the second temporary current bias value, the operating time, and the temperature rise value, a second corrected current bias value is determined; based on the third temporary current bias value, the operating time, and the temperature rise value, a third corrected current bias value is determined.

3. The current bias compensation control method according to claim 2, characterized in that, The first corrected current bias value is determined based on the first temporary current bias value, the running time, and the temperature rise value. The second corrected current bias value is determined based on the second temporary current bias value, the operating time, and the temperature rise value; The third corrected current bias value is determined based on the third temporary current bias value, the operating time, and the temperature rise value, including: A mapping table is pre-established to show the correspondence between the running time, the temperature rise value, and the current bias adjustment coefficient; Based on the mapping table, the current bias adjustment coefficient is determined according to the running time and the temperature rise value; The first corrected current bias value is calculated based on the first temporary current bias value and the current bias adjustment coefficient. The second corrected current bias value is calculated based on the second temporary current bias value and the current bias adjustment coefficient; The third corrected current bias value is calculated based on the third temporary current bias value and the current bias adjustment coefficient.

4. The current bias compensation control method according to claim 3, characterized in that, In the mapping table, for every 1 hour increase in the running time, the current bias adjustment coefficient increases by 0.02 to 0.05; for every 5°C increase in the temperature rise, the current bias adjustment coefficient increases by 0.02 to 0.

05.

5. The current bias compensation control method according to claim 3, characterized in that, The first corrected current bias value is equal to the product of the first temporary current bias value and the current bias adjustment coefficient; The second corrected current bias value is equal to the product of the second temporary current bias value and the current bias adjustment coefficient; The third corrected current bias value is equal to the product of the third temporary current bias value and the current bias adjustment coefficient.

6. The current bias compensation control method according to any one of claims 1 to 5, characterized in that, The first temporary current bias value of the U-phase current is determined based on the first electrical angle. Based on the second electrical angle, determine the second temporary current bias value of the V-phase current; Based on the third electrical angle, the third temporary current bias value of the W-phase current is determined, including: When the servo motor is at the first electrical angle, the first sampled current value of the U-phase current is obtained, and the first sampled current value is used as the first temporary current bias value. When the servo motor is at the second electrical angle, the second sampled current value of the V-phase current is obtained, and the second sampled current value is used as the second temporary current bias value; When the servo motor is at the third electrical angle, the third sampled current value of the W-phase current is obtained, and the third sampled current value is used as the third temporary current bias value.

7. The current bias compensation control method according to any one of claims 1 to 5, characterized in that, The first corrected current value is equal to the difference between the first real-time current value and the first corrected current bias value; The second corrected current value is equal to the difference between the second real-time current value and the second corrected current bias value; The third corrected current value is equal to the difference between the third real-time current value and the third corrected current bias value.

8. A current bias compensation control device, characterized in that, include: An electrical angle acquisition unit (310) is used to acquire the electrical angle of the servo motor (110) through an encoder (120); An initial electrical angle acquisition unit (320) is used to acquire the electrical angle corresponding to each phase current in the three-phase current when it is in a zero-current state; wherein, the three-phase current includes U-phase current, V-phase current and W-phase current, the electrical angle corresponding to the U-phase current when it is in a zero-current state is the first electrical angle, the electrical angle corresponding to the V-phase current when it is in a zero-current state is the second electrical angle, and the electrical angle corresponding to the W-phase current when it is in a zero-current state is the third electrical angle; The temporary current bias value determination unit (330) is used to determine a first temporary current bias value of the U-phase current based on the first electrical angle; determine a second temporary current bias value of the V-phase current based on the second electrical angle; and determine a third temporary current bias value of the W-phase current based on the third electrical angle. The corrected current bias value determination unit (340) is used to determine a first corrected current bias value for the U-phase current based on the first temporary current bias value, the running time of the servo motor (110), and the running temperature; to determine a second corrected current bias value for the V-phase current based on the second temporary current bias value, the running time, and the running temperature; and to determine a third corrected current bias value for the W-phase current based on the third temporary current bias value, the running time, and the running temperature. The corrected current value calculation unit (350) is used to calculate the first corrected current value of the U-phase current based on the first real-time current value and the first corrected current bias value of the U-phase current; to calculate the second corrected current value of the V-phase current based on the second real-time current value and the second corrected current bias value of the V-phase current; and to calculate the third corrected current value of the W-phase current based on the third real-time current value and the third corrected current bias value of the W-phase current.

9. An electronic device, characterized in that, include: A memory (410) and a processor (420), wherein the memory (410) stores a program or instructions executable on the processor (420), and the processor (420) implements the steps of the current bias compensation control method as described in any one of claims 1 to 7 when executing the program or instructions.

10. 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 current bias compensation control method as described in any one of claims 1 to 7.

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