Servo system rotational inertia identification method and system

Abstract

The invention relates to a servo system rotational inertia identification method and system, and the method comprises the steps: switching a servo system to a rotating speed operation mode, and transmitting and executing a first preset final rotating speed instruction; the current rotating speed is collected till the current rotating speed is equal to the first preset final rotating speed, a first preset initial rotating speed instruction is sent out and executed, and the first preset final rotating speed is larger than the first preset initial rotating speed; collecting the electromagnetic torque, the rotating speed and the duration of the speed reduction stage according to a preset sampling period until the current rotating speed is equal to a first preset initial speed; a first preset final rotation speed instruction is sent and executed, and the duration time of the acceleration stage is equal to that of the deceleration stage; collecting the electromagnetic torque and the rotating speed in the acceleration stage according to a preset sampling period until the current rotating speed is equal to a first preset final speed; and the rotational inertia is identified according to the data acquired in the speed reduction and acceleration stages. According to the identification method and system for the rotational inertia of the servo system, the rotational inertia of the servo system is accurately identified, and the optimal setting of the rotating speed ring PI parameter is realized.

Description

A method and system for identifying the rotational inertia of a servo system Technical Field

[0001] This invention relates to the field of motor technology, and specifically to a method and system for identifying the viscosity coefficient and moment of inertia of a servo system. Background Technology

[0002] Servo systems use position, orientation, and attitude as control variables to enable the driven mechanism to continuously, automatically, and precisely follow specified parameters.

[0003] Changes in the input signal. When tuning the parameters of the speed loop controller according to the servo system performance indicators, the parameters of the speed loop controller directly affect the bandwidth of the speed loop, and the parameters of the speed loop controller are related to the moment of inertia and viscosity coefficient of the motor. Therefore, the moment of inertia and viscosity coefficient of the motor directly affect the control performance of the servo system.

[0004] Currently, the identification scheme for moment of inertia usually ignores the viscosity coefficient of the motor to simplify the motor's motion equation. Then, the speed and torque signals under the motor's acceleration and deceleration conditions are used to identify the moment of inertia in combination with the simplified motion equation. However, the identification accuracy of moment of inertia drops significantly under conditions with a large viscosity coefficient, which significantly reduces the accuracy of the identification algorithm. In addition, since the speed loop PI parameter tuning equation includes the viscosity coefficient, existing identification methods are difficult to achieve optimal tuning of the speed loop PI parameters. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for identifying the rotational inertia of a servo system, accurately identifying the rotational inertia of the servo system, and achieving optimal tuning of the rotational speed loop PI parameters.

[0006] In a first aspect, the present invention discloses a method for identifying the rotational inertia of a servo system, the steps of which include:

[0007] S1. The servo system switches to speed operation mode and issues and executes the first preset final speed command;

[0008] S2. Collect the current rotation speed and determine whether the current rotation speed is equal to the first preset final rotation speed. If yes, proceed to step S3; otherwise, proceed to step S2.

[0009] S3. Issue and execute a first preset initial speed command, wherein the first preset final speed is greater than the first preset initial speed;

[0010] S4. Collect the electromagnetic torque, speed and duration of the deceleration phase according to the preset sampling period until the current speed is equal to the first preset initial speed;

[0011] S5. Issue and execute the first preset final speed command;

[0012] S6. Collect the electromagnetic torque and rotational speed during the acceleration phase according to a preset sampling period until the current rotational speed equals the first preset final speed; wherein the duration of the acceleration phase is equal to the duration of the deceleration phase.

[0013] S7. Based on the data collected during the deceleration phase and the acceleration phase, the moment of inertia is identified. The equation for identifying the moment of inertia is:

[0014] ;

[0015] Among them, J est Let be the moment of inertia; ΔT be the duration of the acceleration phase or the deceleration phase; n be the total number of discrete sampling points in the acceleration phase, and also the total number of discrete sampling points in the deceleration phase; T ace (i) represents the electromagnetic torque at the i-th sampling point during the acceleration phase, 0 <i≤n;ω 1i T is the angular velocity of the i-th sampling point during the acceleration phase; dce (i) represents the electromagnetic torque at the i-th sampling point during the deceleration phase; ω 2i ω is the angular velocity of the i-th sampling point during the deceleration phase; 2i ω is the initial angular velocity during the deceleration phase. 2n ω is the final angular velocity of the deceleration phase; 10 ω is the initial angular velocity of the acceleration phase; 1n B is the final angular velocity of the acceleration phase; B is the viscosity coefficient, which is obtained by looking up a table or by a preset viscosity coefficient identification step.

[0016] Optionally, after the servo system switches to the speed operation mode and before the first preset final speed command is issued and executed, the preset viscosity coefficient identification step is performed.

[0017] Optionally, the preset viscosity coefficient identification step includes:

[0018] S01, Issue and execute the second preset initial speed command;

[0019] S02. Collect the current rotation speed and determine whether the current rotation speed is equal to the second preset initial rotation speed. If yes, proceed to step S03; otherwise, repeat step S02.

[0020] S03. Issue the m-th target speed command and execute the m-th target speed command according to the preset speed increment. The m-th target speed is equal to the sum of the second preset final speed and (m-1) times the preset speed increment, where m=1, 2, ..., j, j>0 and is an integer. The second preset final speed is greater than the second preset initial speed.

[0021] S04. Collect the current rotational speed and determine whether the current rotational speed is equal to the target rotational speed for the mth time. If yes, sample the rotational speed and electromagnetic torque, and proceed to step S05; otherwise, repeat step S04.

[0022] S05. Determine whether the number of sampling points has reached the preset number of points. If yes, proceed to step S06; otherwise, repeat step S05.

[0023] S06. Calculate the average speed and average electromagnetic torque for all sampled speeds and electromagnetic torques respectively;

[0024] S07. Determine whether the average rotational speed is greater than or equal to the second preset final rotational speed; if yes, proceed to step S08; otherwise, proceed to step S03.

[0025] S08. The target rotational speed and electromagnetic torque collected m times are combined into a dataset, and the viscosity coefficient is obtained by least squares fitting of the linear equation of the viscosity coefficient.

[0026] Optionally, the linear equation for the viscosity coefficient is:

[0027] ;

[0028] Among them, T e For electromagnetic torque, T c For Coulomb friction, T L Where is the load torque and B is the viscosity coefficient.

[0029] Optionally, the formula for the speed increment is:

[0030] ;

[0031] Among them, S n S represents the speed increment; fin The second preset initial rotational speed; S ini The second preset final speed; S fin >S ini N s This is the preset number of samples for linear regression.

[0032] Optional, N s The value range is [10, 30].

[0033] Optionally, the preset number of points can be in the range of [500, 3000].

[0034] Optionally, the duration of the deceleration phase is equal to the preset sampling period multiplied by the number of sampling points in the deceleration phase.

[0035] Secondly, the present invention discloses a servo system rotational inertia identification system for performing the above-described servo system rotational inertia identification method, the steps of which include:

[0036] The control module is used to send control signals to the servo system, motor, moment of inertia identification module, acquisition module, and moment of inertia identification module.

[0037] Acquisition module; used to acquire electromagnetic torque, speed, and duration during deceleration and acceleration phases;

[0038] The moment of inertia identification module is used to identify the moment of inertia based on the data collected during the deceleration and acceleration phases; the identification equation for the moment of inertia is:

[0039] ;

[0040] Among them, J est Let be the moment of inertia; ΔT be the duration of the acceleration phase or the deceleration phase; n be the total number of discrete sampling points in the acceleration phase, and also the total number of discrete sampling points in the deceleration phase; T ace (i) represents the electromagnetic torque at the i-th sampling point during the acceleration phase, 0 <i≤n;ω 1i T is the angular velocity of the i-th sampling point during the acceleration phase; dce (i) represents the electromagnetic torque at the i-th sampling point during the deceleration phase; ω 2i ω is the angular velocity of the i-th sampling point during the deceleration phase; 2i ω is the initial angular velocity during the deceleration phase. 2n ω is the final angular velocity of the deceleration phase; 10 ω is the initial angular velocity of the acceleration phase; 1n B is the final angular velocity of the acceleration phase; B is the viscosity coefficient, which is obtained by looking up a table or by a preset viscosity coefficient identification step.

[0041] The control module, the acquisition module, and the moment of inertia identification module are connected in sequence.

[0042] Optionally, it also includes a viscosity coefficient identification module for performing a preset viscosity coefficient identification step, wherein the acquisition module, the viscosity coefficient identification module and the moment of inertia identification module are connected in sequence.

[0043] The beneficial effects of this invention are:

[0044] (1) The viscosity coefficient, friction electromagnetic torque and load electromagnetic torque of the servo motor are not ignored during the identification process, which can achieve more accurate identification of the rotational inertia of the servo system and the identification accuracy is high.

[0045] (2) By combining and subtracting the electromagnetic torque-speed expressions for the acceleration and deceleration phases, the Coulomb friction torque and load torque terms for identifying the moment of inertia are eliminated, simplifying the calculation process for identifying the moment of inertia.

[0046] (3) Based on the least squares fitting method, a linear relationship model between the speed and the electromagnetic torque is established to achieve accurate identification of the viscosity coefficient of the motor. Attached Figure Description

[0047] Figure 1 is a flowchart of the method for identifying the rotational inertia of the servo system according to an embodiment of the present invention;

[0048] Figure 2 is a flowchart of identifying the viscosity coefficient in an embodiment of the present invention;

[0049] Figure 3 is a waveform diagram of rotational speed for identifying moment of inertia and viscosity coefficient in an embodiment of the present invention;

[0050] Figure 4 is a schematic diagram of the servo system rotational inertia identification system in an embodiment of the present invention.

[0051] Explanation of reference numerals in the attached diagram: 1-Control module; 2-Acquisition module; 3-Moment of inertia identification module; 4-Viscosity coefficient identification module. Detailed Implementation

[0052] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0053] Referring to Figures 1 and 3, this embodiment of the invention discloses a method for identifying the rotational inertia of a servo system, the steps of which include:

[0054] S1. The servo system switches to speed operation mode, issues and executes the first preset final speed command; when the servo system switches to speed operation mode, the initial speed value is 0. The first preset final speed command indicates that the motor speed is adjusted to the first preset final speed.

[0055] S2. Collect the current rotational speed and determine whether the current rotational speed is equal to the first preset final rotational speed. If yes, proceed to step S3; otherwise, proceed to step S2.

[0056] S3. Issue and execute the first preset initial speed command, wherein the first preset final speed is greater than the first preset initial speed; the first preset initial speed command indicates that the motor speed is adjusted to the first preset initial speed.

[0057] S4. Collect the electromagnetic torque, speed and duration of the deceleration phase according to the preset sampling period until the current speed is equal to the first preset initial speed.

[0058] S5. Issue and execute the first preset final speed command;

[0059] S6. Collect the electromagnetic torque and rotational speed during the acceleration phase according to a preset sampling period until the current rotational speed equals the first preset final speed; wherein the duration of the acceleration phase is equal to the duration of the deceleration phase.

[0060] S7. Based on the data collected during the deceleration and acceleration phases, the moment of inertia is identified. The equation for identifying the moment of inertia is:

[0061] ;

[0062] Among them, J est Let be the moment of inertia; ΔT be the duration of the acceleration phase or the deceleration phase; n be the total number of discrete sampling points in the acceleration phase, and also the total number of discrete sampling points in the deceleration phase; T ace (i) represents the electromagnetic torque at the i-th sampling point during the acceleration phase, 0 <i≤n;ω 1i T is the angular velocity of the i-th sampling point during the acceleration phase; dce (i) represents the electromagnetic torque at the i-th sampling point during the deceleration phase; ω 2i ω is the angular velocity of the i-th sampling point during the deceleration phase; 2i ω is the initial angular velocity during the deceleration phase. 2n ω is the final angular velocity of the deceleration phase; 10 ω is the initial angular velocity of the acceleration phase; 1n B is the final angular velocity of the acceleration phase; B is the viscosity coefficient, which is obtained by looking up a table or by a preset viscosity coefficient identification step.

[0063] The motor is brought into a state of deceleration followed by acceleration, and electromagnetic torque and speed signals are collected during both acceleration and deceleration phases. The duration of the deceleration phase must be equal to the duration of the acceleration phase. Based on the speed and electromagnetic torque signals, the rotational inertia of the servo system is accurately identified, and the speed loop PI parameters of the servo system are tuned using the aforementioned identification parameters to improve the control bandwidth and response speed of the servo system. Compared with existing acceleration and deceleration methods, this invention can identify the rotational inertia of the servo system without neglecting the viscosity coefficient, friction electromagnetic torque, and load electromagnetic torque of the servo motor during the identification process. This characteristic makes its identification accuracy significantly better than existing technologies. By simultaneously subtracting the electromagnetic torque-speed expressions for the acceleration and deceleration phases, the friction electromagnetic torque and load electromagnetic torque terms are eliminated, resulting in the identification equation for the rotational inertia, simplifying the calculation process for identifying the rotational inertia.

[0064] In another embodiment, the current rotational speed is collected, and it is determined whether the current rotational speed is equal to a first preset final rotational speed. If so, proceed to step S3; otherwise, proceed to step S2; including the following steps:

[0065] The current rotational speed is collected, and it is determined whether the current rotational speed is equal to a first preset final rotational speed and has lasted for a first preset time. If so, proceed to step S3; otherwise, proceed to step S2. In this invention, not only is it determined whether the current rotational speed is equal to the first preset final rotational speed, but it is also determined whether it has lasted for a first preset time, ensuring that the current rotational speed reaches and remains stably at the first preset final rotational speed. For example, referring to Figure 3, the first preset time is greater than 0s. In some embodiments, the first preset time can be 0.03s, 0.02s, 0.05s, 1s, 2s, or other values, and is not limited thereto; it can be set according to the actual situation.

[0066] In another embodiment, the electromagnetic torque, rotational speed, and duration of the deceleration phase are collected at a preset sampling period until the current rotational speed equals the first preset initial velocity; this includes performing the following steps:

[0067] The electromagnetic torque, speed, and duration of the deceleration phase are collected according to a preset sampling period until the current speed is equal to the first preset initial speed and lasts for a second preset time.

[0068] In another embodiment, the electromagnetic torque and rotational speed during the acceleration phase are collected at a preset sampling period until the current rotational speed equals a first preset final speed; this includes performing the following steps:

[0069] The electromagnetic torque and speed during the acceleration phase are collected according to a preset sampling period until the current speed equals the first preset final speed and continues for a third preset time.

[0070] For example, referring to Figure 3, both the second preset time and the third preset time are greater than 0s. In some embodiments, the second preset time and the third preset time can be 0.1s, 0.2s, 0.3s, 0.35s, or other values, and are not limited thereto. They can be set according to the actual situation.

[0071] In this embodiment of the application, after the servo system switches to the speed operation mode and before issuing and executing the first preset final speed command, a preset viscosity coefficient identification step is performed.

[0072] Referring to Figures 1 to 3, the preset viscosity coefficient identification steps include:

[0073] S01, Issue and execute the second preset initial speed command; the second preset initial speed command indicates that the motor speed is adjusted to the second preset initial speed.

[0074] S02. Collect the current rotation speed and determine whether the current rotation speed is equal to the second preset initial rotation speed. If yes, proceed to step S03; otherwise, repeat step S02.

[0075] S03. Issue the m-th target speed command and execute the m-th target speed command according to the preset speed increment. The m-th target speed is equal to the sum of the second preset final speed and (m-1) times the preset speed increment, where m = 1, 2, ..., j, j > 0 and is an integer. The second preset final speed is greater than the second preset initial speed. The m-th target speed command indicates that the motor is to be adjusted from the current speed to the m-th target speed.

[0076] S04. Collect the current rotational speed and determine whether the current rotational speed is equal to the target rotational speed for the mth time. If so, sample the rotational speed and electromagnetic torque, and proceed to step S05; otherwise, repeat step S04.

[0077] S05. Determine whether the number of sampling points has reached the preset number of points. If yes, proceed to step S06; otherwise, repeat step S05.

[0078] S06. Calculate the average speed and average electromagnetic torque for all sampled speeds and electromagnetic torques respectively;

[0079] S07. Determine whether the average rotational speed is greater than or equal to the second preset final rotational speed; if yes, proceed to step S08; otherwise, proceed to step S03.

[0080] S08. The target rotational speed and electromagnetic torque collected m times are combined into a dataset, and the viscosity coefficient is obtained by least squares fitting of the linear equation of the viscosity coefficient.

[0081] In this invention, the viscosity coefficient identification precedes the moment of inertia identification, and the viscosity coefficient serves as a key input parameter for the moment of inertia identification algorithm. Based on the least squares fitting method, a linear relationship model between rotational speed and electromagnetic torque is established to achieve accurate identification of the motor's viscosity coefficient. Specifically, the servo system is in speed loop mode. Viscosity coefficient identification begins when an enable signal of 1 is received. This method calculates the speed increment based on a second preset initial speed, a first target speed, and the number of linear regression samples. Subsequently, the speed and electromagnetic torque signals at steady state are collected to ensure the stability of the sample data. Then, based on the speed and electromagnetic torque samples, the least squares method is used to derive the linear regression equation, the slope of which is an estimate of the viscosity coefficient B. Compared to existing acceleration / deceleration methods, this invention can simultaneously identify the servo system's moment of inertia and viscosity coefficient, and it does not neglect the frictional electromagnetic torque and load electromagnetic torque of the servo motor during the identification process. This characteristic makes its identification accuracy significantly superior to existing technologies. Figure 3 shows the rotational speed waveform for identifying the moment of inertia and viscosity coefficient in an embodiment of the present invention. This waveform illustrates the states during the moment of inertia identification stage and the viscosity coefficient identification stage. For example, referring to Figure 3, the second preset initial speed and the second preset final speed are 600 and 1100 respectively, and the first preset initial speed and the first preset final speed during the acceleration / deceleration stage are 600 and 1000 respectively. Therefore, the speed increment in the figure is 50. After collecting speed and torque samples under uniform operating conditions, the viscosity coefficient is identified using these samples and least-squares linear fitting. Subsequently, the method adjusts the speed to 1000 and stabilizes it, then first decelerates to 600 and then accelerates to 1000, collecting electromagnetic torque and speed information during acceleration and deceleration. After data sampling, the collected information and the viscosity coefficient are substituted into the moment of inertia identification equation to calculate the moment of inertia. Then, the viscosity coefficient and moment of inertia are stored in a memory for tuning the speed loop PI parameters.

[0082] In this embodiment, the linear equation for the viscosity coefficient is:

[0083] ;

[0084] Among them, T e For electromagnetic torque, T c T is the Coulomb friction torque. L Let B be the load torque and B be the viscosity coefficient. The motor's equation of motion forms the basis for the algorithm to identify the moment of inertia, and its specific mathematical expression is as follows: In the formula, T e ω is the electromagnetic torque of the motor; J is the moment of inertia of the motor; B is the viscosity coefficient; ω is the motor speed; T is the electromagnetic torque of the motor. c T is the Coulomb friction torque. L Let be the load torque. When the motor is at a constant speed and rotating in the positive direction, the equation of motion will be rewritten as: When the direction of motor speed remains unchanged, the electromagnetic torque T e It has a linear relationship with the angular velocity ω, where the slope is the viscosity coefficient B and the intercept is the Coulomb friction torque T. c With load torque T L sum.

[0085] In this embodiment, the formula for the speed increment is:

[0086] ;

[0087] Among them, S n S represents the speed increment; fin The second preset final speed; S ini The second preset initial rotational speed; N s This is the preset number of samples for linear regression.

[0088] In the embodiments of this application, N s The value range is [10, 30].

[0089] In this embodiment of the application, the preset number of points ranges from [500, 3000].

[0090] In this embodiment, the duration of the deceleration phase is equal to the preset sampling period multiplied by the number of sampling points in the deceleration phase. Since the sampling periods for both the acceleration and deceleration phases are set values, it is necessary to ensure that the number of sampling points in the acceleration phase is equal to the number of sampling points in the deceleration phase, thereby making the durations of the acceleration and deceleration phases equal, and thus the number of sampling points in the acceleration and deceleration phases is also equal.

[0091] Referring to Figure 4, the present invention also discloses a servo system rotational inertia identification system for performing the above-described servo system rotational inertia identification method, the steps of which include:

[0092] Control module 1 is used to send control signals to the servo system, motor, moment of inertia identification module 1, acquisition module 2, and moment of inertia identification module 3;

[0093] Acquisition module 2; used to acquire electromagnetic torque, speed, and duration during the deceleration and acceleration phases;

[0094] The moment of inertia identification module 3 is used to identify the moment of inertia based on the data collected during the deceleration and acceleration phases; the identification equation for the moment of inertia is:

[0095] ;

[0096] Among them, J estLet be the moment of inertia; ΔT be the duration of the acceleration phase or the deceleration phase; n be the total number of discrete sampling points in the acceleration phase, and also the total number of discrete sampling points in the deceleration phase; T ace (i) represents the electromagnetic torque at the i-th sampling point during the acceleration phase, 0 <i≤n;ω 1i T is the angular velocity of the i-th sampling point during the acceleration phase; dce (i) represents the electromagnetic torque at the i-th sampling point during the deceleration phase; ω 2i ω is the angular velocity of the i-th sampling point during the deceleration phase; 2i ω is the initial angular velocity during the deceleration phase. 2n ω is the final angular velocity of the deceleration phase; 10 ω is the initial angular velocity of the acceleration phase; 1n B is the final angular velocity of the acceleration phase; B is the viscosity coefficient, which is obtained by looking up a table or by a preset viscosity coefficient identification step.

[0097] The control module 1, the data acquisition module 2, and the moment of inertia identification module 3 are connected in sequence. The control module 1 controls the data acquisition module 2 to acquire data, and the data acquisition module 2 outputs the acquired data to the moment of inertia identification module 3 for moment of inertia identification.

[0098] In this embodiment, a viscosity coefficient identification module 4 is further included for performing a preset viscosity coefficient identification step. The acquisition module 2, the viscosity coefficient identification module 4, and the moment of inertia identification module 3 are connected in sequence. The viscosity coefficient identification module 4 receives data from the acquisition module 2 to identify the viscosity coefficient, and then outputs it to the moment of inertia identification module 3 to identify the moment of inertia.

[0099] The present invention provides a method and system for identifying the rotational inertia of a servo system. During the identification process, the viscosity coefficient, frictional electromagnetic torque, and load electromagnetic torque of the servo motor are not ignored, enabling more accurate identification of the rotational inertia of the servo system with high precision. By simultaneously subtracting the electromagnetic torque-speed expressions for the acceleration and deceleration phases, the Coulomb frictional torque and load torque terms for identifying the rotational inertia are eliminated, simplifying the calculation process. Based on the least squares fitting method, a linear relationship model between the speed and electromagnetic torque is established, achieving accurate identification of the motor's viscosity coefficient.

[0100] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for identifying the moment of inertia of a servo system, characterized in that, The steps include: S1. The servo system switches to the speed operation mode, issues and executes the first preset final speed command; S2. The current speed is collected, and it is determined whether the current speed is equal to the first preset final speed. If so, proceed to step S3. Otherwise, proceed to step S2; S3, issue and execute a first preset initial speed command, wherein the first preset final speed is greater than the first preset initial speed; S4, collect the electromagnetic torque, speed, and duration of the deceleration phase according to a preset sampling period until the current speed equals the first preset initial speed; S5, issue and execute a first preset final speed command; S6, collect the electromagnetic torque and speed of the acceleration phase according to a preset sampling period until the current speed equals the first preset final speed; wherein the duration of the acceleration phase is equal to the duration of the deceleration phase; S7, identify the moment of inertia based on the data collected during the deceleration phase and the acceleration phase, wherein the equation for identifying the moment of inertia is: ; among which, J est Let be the moment of inertia; ΔT be the duration of the acceleration phase or the deceleration phase; n be the total number of discrete sampling points in the acceleration phase, and also the total number of discrete sampling points in the deceleration phase; T ace (i) represents the electromagnetic torque at the i-th sampling point during the acceleration phase, 0 <i≤n;ω 1i T is the angular velocity of the i-th sampling point during the acceleration phase; dce (i) represents the electromagnetic torque at the i-th sampling point during the deceleration phase; ω 2i ω is the angular velocity of the i-th sampling point during the deceleration phase; 2i ω is the initial angular velocity during the deceleration phase. 2n ω is the final angular velocity of the deceleration phase; 10 ω is the initial angular velocity of the acceleration phase; 1n B is the final angular velocity of the acceleration phase; B is the viscosity coefficient, which is obtained by looking up a table or by a preset viscosity coefficient identification step.

2. The method for identifying the rotational inertia of a servo system according to claim 1, characterized in that, After the servo system switches to the speed operation mode and before the first preset final speed command is issued and executed, the preset viscosity coefficient identification step is performed.

3. The method for identifying the rotational inertia of a servo system according to claim 2, characterized in that, The preset viscosity coefficient identification steps include: S01, issuing and executing a second preset initial speed command; S02, acquiring the current speed, determining whether the current speed is equal to the second preset initial speed, if yes, proceeding to step S03; otherwise, repeating step S02; S03, issuing the m-th target speed command, executing the m-th target speed command according to a preset speed increment, the m-th target speed being equal to the sum of the second preset final speed and (m-1) times the preset speed increment, m=1, 2, ..., j, j>0 and is an integer, the second preset final speed being greater than the second preset initial speed; S04, acquiring the current speed, determining whether the current speed is equal to the second preset initial speed. If the target rotational speed is m times, sample the rotational speed and electromagnetic torque, and proceed to step S05; otherwise, repeat step S04. S05: Determine if the number of sampling points has reached the preset number. If yes, proceed to step S06; otherwise, repeat step S05. S06: Calculate the average rotational speed and average electromagnetic torque for all sampled rotational speeds and electromagnetic torques. S07: Determine if the average rotational speed is greater than or equal to the second preset final rotational speed. If yes, proceed to step S08; otherwise, proceed to step S03. S08: Combine the m sampled target rotational speeds and electromagnetic torques into a dataset, and perform least squares fitting on the linear equation of the viscosity coefficient to obtain the viscosity coefficient.

4. The method for identifying the rotational inertia of a servo system according to claim 3, characterized in that, The linear equation for the viscosity coefficient is: Among them, T e For electromagnetic torque, T c For Coulomb friction, T L Where is the load torque and B is the viscosity coefficient.

5. The method for identifying the moment of inertia of a servo system according to claim 3, characterized in that, The formula for the speed increment is: Among them, S n S represents the speed increment; fin The second preset initial rotational speed; S ini The second preset final speed; S fin >S ini N s This is the preset number of samples for linear regression.

6. The method for identifying the moment of inertia of a servo system according to claim 5, characterized in that, N s The value range is [10, 30].

7. The method for identifying the moment of inertia of a servo system according to claim 3, characterized in that, The preset number of points ranges from [500, 3000].

8. The method for identifying the moment of inertia of a servo system according to claim 1, characterized in that, The duration of the deceleration phase is equal to the preset sampling period multiplied by the number of sampling points in the deceleration phase.

9. A system for identifying the rotational inertia of a servo system, used to execute the method for identifying the rotational inertia of a servo system according to any one of claims 1 to 8, characterized in that the steps include... include: The control module (1) is used to send control signals to the servo system, motor, moment of inertia identification module (1), acquisition module (2), and moment of inertia identification module (3); the acquisition module (2) is used to acquire the electromagnetic torque, speed, and duration during the deceleration and acceleration phases. The moment of inertia identification module (3) is used to identify the moment of inertia based on the data collected during the deceleration phase and the acceleration phase; the identification equation for the moment of inertia is: ; among which, J est Let be the moment of inertia; ΔT be the duration of the acceleration phase or the deceleration phase; n be the total number of discrete sampling points in the acceleration phase, and also the total number of discrete sampling points in the deceleration phase; T ace (i) represents the electromagnetic torque at the i-th sampling point during the acceleration phase, 0 <i≤n;ω 1i The angular velocity of the i-th sampling point during the acceleration phase; T dce (i) represents the electromagnetic torque at the i-th sampling point during the deceleration phase; ω 2i ω is the angular velocity of the i-th sampling point during the deceleration phase; 2i ω is the initial angular velocity during the deceleration phase. 2n ω is the final angular velocity of the deceleration phase; 10 ω is the initial angular velocity of the acceleration phase; 1n B is the final angular velocity of the acceleration phase; B is the viscosity coefficient, which is obtained by looking up a table or by a preset viscosity coefficient identification step; the control module (1), the acquisition module (2) and the moment of inertia identification module (3) are connected in sequence.

10. The servo system rotational inertia identification system according to claim 9, characterized in that, It also includes a viscosity coefficient identification module (4) for performing preset viscosity coefficient identification steps, wherein the acquisition module (2), the viscosity coefficient identification module (4) and the moment of inertia identification module (3) are connected in sequence.

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