CN115524962B - A PROFINET dynamic servo control method for servo drives - Google Patents

Abstract

The invention discloses a servo driver PROFINET dynamic servo control method, which comprises calculating a servo position loop instruction interpolation starting point according to an application period multiplying power K_cacf and a cache position information Pos^kCalculating a time correction coefficient C_t according to the read time T_i and the output time T_o of the upper controller and the servo position loop instruction period T_casr, and interpolating a starting point based on the current servo position loop instruction beat i and the number of beats N, the time correction coefficient C_t, the cache position information Pos^k and the servo position loop instruction interpolationCalculating servo position loop interpolation position instructions in real timeThe invention can effectively avoid the problem of process shaft following error degradation caused by the change of the applied cycle multiplying power or the change of the parameters of the control system.

Description

Dynamic servo control method for servo driver PROFINET

Technical Field

The invention relates to the technical field of servo driver control, in particular to a servo driver PROFINET dynamic servo control method.

Background

With the continuous iteration of modern industrial automation, domestic servo manufacturers have recently begun to be involved in the development and commercialization of PROFINET servo drives, with PROFINET dynamic servo control technology being of particular interest. The existing servo driver PROFINET dynamic servo control method has the following two problems limited by objective factors:

1. The method ignores the influence of the application period multiplying power, and when the application period multiplying power K_cacf is more than or equal to 2, the actual industrial Ethernet control system can cause obvious degradation of the process shaft following error due to the limitation of objective factors, so that a design scheme with higher cost is passively selected;

2. The method ignores the influence of the reading time and the output time of an upper controller, and the industrial Ethernet control system can cause the degradation of the following error of the process shaft after changing the reading time and the output time due to the synchronous requirement, and can cause the consistency degradation of the following error of the process shaft even after changing the track planning speed.

Disclosure of Invention

The invention provides a servo driver PROFINET dynamic servo control method, which aims to overcome the defects of the prior art and avoid the problem of process shaft following error degradation caused by the change of an application period multiplying power or the change of a control system parameter.

The technical scheme of the invention is as follows:

a servo driver PROFINET dynamic servo control method comprises the following steps:

S1, calculating an interpolation starting point of a servo position loop instruction according to an application period multiplying power K_cacf and cache position information Pos^k

S2, calculating a time correction coefficient C_t according to the reading time T_i and the output time T_o of the upper controller and the servo position loop instruction period T_casr;

S3, based on the current servo position loop instruction beat i and the beat number N, the time correction coefficient C_t, the buffer position information Pos^k and the servo position loop instruction interpolation starting pointCalculating servo position loop interpolation position instructions in real time

Further, step S1 indicates the interpolation starting point of the servo position loop commandThe calculation method of (1) is as follows:

wherein Pos^k＝0 is the cache location information of the current application period, and Pos^k＝1 is the cache location information of the previous application period.

Further, the calculation method of the time correction coefficient C_t in step S2 is as follows:

C_t＝0.5×(T_i％T_casr+T_o％T_casr+2)

wherein, "%" represents the remainder operation.

Further, step S3 is a servo position loop interpolation position commandThe calculation method of (1) is as follows:

Wherein the position loop instructs the interpolation beat numberThe current servo position loop instruction beat i e 0, N-1.

Compared with the prior art, the method has the advantages that the method calculates the interpolation starting point of the servo position loop instruction according to the application period multiplying power K_cacf and the cached position information Pos^kWhen the application period multiplying power K_cacf is more than or equal to 2, the process shaft following error can be still ensured to be at a very high level, a time correction coefficient C_t is calculated according to the reading time T_i and the output time T_o of the upper controller and the servo position loop instruction period T_casr, and the interpolation starting point is interpolated based on the current servo position loop instruction beat i and beat number N, the time correction coefficient C_t, the cache position information Pos^k and the servo position loop instructionCalculating servo position loop interpolation position instructions in real timeAfter the track planning speed is changed and the reading time and the output time of the upper controller are changed due to the synchronous requirement, the following error of the process shaft can be still ensured, and the method has good social and economic values.

Drawings

FIG. 1 is a flow chart of the present invention;

FIG. 2 is a schematic diagram of the synchronization logic of the present invention.

Detailed Description

The technical scheme of the invention is described in detail below with reference to the accompanying drawings:

Referring to fig. 1, a servo driver PROFINET dynamic servo control method includes the following steps:

S1, calculating an interpolation starting point of a servo position loop instruction according to an application period multiplying power K_cacf and cache position information Pos^k

Wherein Pos^k＝0 is the cache location information of the current application period, and Pos^k＝1 is the cache location information of the previous application period.

S2, as shown in FIG. 2, in each synchronization period T_cyc, the PWM zero crossing point of the servo driver FPGA is synchronous with the PROFINET period synchronization pulse PN_cyc, the servo driver CPU responds to the PN_in pulse interrupt request of PROFINET and completes the Host_out period transmission before executing the speed loop, and after scanning the PN_out pulse interrupt request mark of PROFINET, the servo driver CPU completes the Host_in period reception before executing the position loop instruction interpolation. In the figure, T_pwm is the servo driver FPGA PWM period, and period T_cacf＝K_cacf×T_cyc is applied.

Calculating a time correction coefficient C_t according to the read time T_i and the output time T_o of the upper controller and the servo position loop instruction period T_casr:

C_t＝0.5×(T_i％T_casr+T_o％T_casr+2)

Wherein T_i、T_o and T_casr are integer multiples of 125us, "%" represents remainder operation, and C_t is floating point number.

S3, based on the current servo position loop instruction beat i and the beat number N, the time correction coefficient C_t, the buffer position information Pos^k and the servo position loop instruction interpolation starting pointCalculating servo position loop interpolation position instructions in real time

Wherein the position loop instructs the interpolation beat numberThe current servo position loop instruction beat i e 0, N-1.

In the actual working process, a user can select different application period multiplying powers K_cacf according to objective factors, and after the reading time and the output time of the upper controller or the track planning are changed due to the process requirement, the following error of a process shaft can be still ensured.

The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and improvements could be made by those skilled in the art without departing from the inventive concept, which fall within the scope of the present invention.

Claims (1)

Translated fromChinese

1.一种伺服驱动器PROFINET动态伺服控制方法，其特征在于，包括如下步骤：1. A servo drive PROFINET dynamic servo control method, characterized in that it includes the following steps:S1：根据应用周期倍率K_cacf和缓存位置信息Pos^k计算伺服位置环指令插值起始点所述伺服位置环指令插值起始点的计算方法为：S1: Calculate the servo position loop command interpolation starting point based on the application cycle multiplier_Kcacf and cache position information Pos^k The servo position loop command interpolation starting point The calculation method is:其中，Pos^k＝0为当前应用周期的缓存位置信息，Pos^k＝1为前一次应用周期的缓存位置信息；Wherein, Pos^k=0 is the cache position information of the current application cycle, and Pos^k=1 is the cache position information of the previous application cycle;S2：根据上位控制器的读取时间T_i和输出时间T_o以及伺服位置环指令周期T_casr计算时间校正系数C_t；S2: Calculate the time correction coefficient C_t according to the reading time_Ti and output time_To of the upper controller and the servo position loop instruction cycle T_casr ;所述时间校正系数C_t的计算方法为：The calculation method of the time correction coefficient C_t is:C_t＝0.5×(T_i％T_casr+T_o％T_casr+2)C_t =0.5×(T_i %T_casr +T_o %T_casr +2)其中，“％”表示取余运算；Among them, "%" represents the remainder operation;S3：基于当前伺服位置环指令节拍i和节拍数N、时间校正系数C_t、缓存位置信息Pos^k和伺服位置环指令插值起始点实时计算伺服位置环插值位置指令S3: Based on the current servo position loop instruction beat i and beat number N, time correction coefficient C_t , cache position information Pos^k and servo position loop instruction interpolation starting point Real-time calculation of servo position loop interpolation position commandS3所述伺服位置环插值位置指令的计算方法为：S3: Servo position loop interpolation position command The calculation method is:其中，位置环指令插值节拍数当前伺服位置环指令节拍i∈[0，N-1]；T_cyc是同步周期。Among them, the position loop command interpolation beat number The current servo position loop command beat i∈[0, N-1]; T_cyc is the synchronization period.