A rudder control method based on integral saturation optimization and commutation differential enhancement

Abstract

The application discloses a rudder control method based on integral saturation optimization and commutation differential enhancement, and belongs to the technical field of motor control, and solves the problems of integral saturation, commutation impact and steady-state jitter of traditional PID control. The method comprises the following steps: generating a real-time position error according to a real-time target position and a real-time position feedback signal of an electric rudder; judging whether the electric rudder enters a steady state according to the change of the real-time position error and the real-time target position; if the electric rudder does not enter the steady state, performing amplitude limiting output on a position loop according to the change rate of the real-time position error and the real-time target position, so as to perform direction and commutation control on the electric rudder and perform amplitude limiting output on a current loop, and driving the electric rudder to operate; and if the electric rudder enters the steady state, controlling the output of the position loop to be 0, clearing the integral term of the current loop, and not operating the electric rudder.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor control, in particular to a rudder control method based on integral saturation optimization and commutation differential enhancement, which is particularly suitable for a servo rudder system requiring high-precision position control. BACKGROUND

[0002] As a high-precision servo actuator, the rudder is widely used in robot joint driving, aerospace rudder adjustment, and precise instrument attitude control, etc. Its core performance indicators reflect the rapidity, stability and smoothness of position tracking. The current mainstream rudder system mostly adopts PID (Proportion-Integral-Derivative) control algorithm, and realizes accurate regulation and control through the multi-level closed-loop architecture of position loop, speed loop and current loop. However, the traditional PID control has significant defects under the specific working conditions of the rudder, which are specifically manifested in the following three key problems:

[0003] (1) Integral saturation problem: output overshoot in position locking or commutation process

[0004] The control output of the rudder is physically limited due to mechanical structure constraints (such as maximum angle and maximum torque). In the position locking stage (the target position is unchanged but there is a small static error) or the commutation process (the target position is reversed), the integral term of the traditional PID will be excessively accumulated due to the continuous accumulation of errors ( "integral saturation"). For example, when the rudder has reached the mechanical limit but the target position has not been adjusted, the integral term will continue to increase to "eliminate errors", resulting in a significant overshoot or oscillation when the target position is adjusted, which seriously affects the position locking accuracy.

[0005] (2) Commutation impact problem: differential disturbance and mechanical vibration when switching direction

[0006] When the direction of the rudder driving motor (such as permanent magnet synchronous motor, stepper motor) is switched (commutation), the switching of the three-phase winding current will cause the position, speed and other feedback signals to appear transient mutations (such as Hall sensor signal jump, current detection ripple). The differential term of the traditional PID is directly calculated based on the instantaneous rate of change of error, which is extremely sensitive to such mutations, and will produce sharp differential output pulses, causing instantaneous impact of motor torque, resulting in mechanical jitter, gear meshing noise or position overshoot of the rudder at the commutation moment, which not only reduces the control smoothness, but also aggravates the wear of the transmission components.

[0007] (3) Steady jitter problem: output fluctuation under small error

[0008] When the steering engine approaches the target position (small position following error), the output of the traditional PID may still continue to adjust due to the slight fluctuation of the error (such as sensor noise, mechanical friction disturbance): the proportional term will amplify the slight error, the differential term will capture high-frequency noise, and the integral term may slowly accumulate due to the existence of static error, resulting in small oscillation ( "steady-state jitter") around the target value. This jitter is particularly evident in high-precision scenarios (such as aerospace rudder fine-tuning), which can reduce the position holding accuracy of the system and even cause resonance risk.

[0009] The root cause of the above problem is that the traditional PID control is not designed to adapt to the mechanical constraints, commutation dynamic characteristics and steady-state accuracy requirements of the steering engine, resulting in a difficult balance between integral saturation suppression, differential disturbance rejection capability and steady-state convergence. Therefore, there is an urgent need for a control method that integrates integral saturation optimization and commutation differential enhancement to solve the core defects of traditional PID control in steering engine control and improve its overall performance in high-precision scenarios. SUMMARY

[0010] In view of the above analysis, the embodiments of the present application aim to provide a steering engine control method based on integral saturation optimization and commutation differential enhancement to solve the problems of integral saturation, commutation impact and steady-state jitter of traditional PID control.

[0011] The present application discloses a steering engine control method based on integral saturation optimization and commutation differential enhancement, the method comprising:

[0012] generating a real-time position error according to the real-time target position and the real-time position feedback signal of the electric steering engine; and determining whether the electric steering engine enters a steady state according to the change of the real-time position error and the real-time target position;

[0013] If the electric steering engine does not enter the steady state, performing amplitude limiting output on the position loop according to the change rate of the real-time position error and the real-time target position, to drive the electric steering engine to run by limiting the amplitude output of the direction and commutation control and the current loop of the electric steering engine;

[0014] If the electric steering engine enters the steady state, setting the output of the position loop to 0, clearing the integral term of the current loop, and the electric steering engine does not run.

[0015] On the basis of the above scheme, the present application further makes the following improvements:

[0016] Further, if the electric steering engine does not enter the steady state, performing:

[0017] performing amplitude limiting output on the position loop according to the change rate of the real-time position error and the real-time target position;

[0018] The limited output of the position loop is taken as the speed output reference to determine the real-time speed output, and the electric steering engine is controlled in direction and commutation;

[0019] The real-time speed output is taken as the real-time target current of the current loop, and the limited output of the current loop is taken as the motor driving signal to drive the steering engine motor to run.

[0020] Further, the position loop is limited output according to the real-time position error and the change rate of the real-time target position, and the following is executed:

[0021] The real-time position error is processed by PID based on integral saturation optimization;

[0022] The speed feedforward of the position loop is calculated according to the change rate of the real-time target position;

[0023] The limited output of the position loop is obtained according to the proportional term, the integral term, the differential term and the speed feedforward of the position loop.

[0024] Further, the proportional term of the position loop is expressed as:

[0025] (1)

[0026] wherein, is the proportional coefficient of the position loop, represents the real-time position error;

[0027] The integral term of the position loop is expressed as:

[0028] (2)

[0029] wherein, is the integral coefficient of the position loop, is the integral term of the position loop of the last period; , and are the limited output and the pre-saturation output of the position loop of the last period respectively;

[0030] The differential term of the position loop is expressed as:

[0031] (3)

[0032] wherein, is the differential coefficient of the position loop, is the proportional term of the position loop of the last period.

[0033] Further, the speed feedforward of the position loop is expressed as:

[0034] (4)

[0035] wherein, is a real-time target position, is a target position of the last period;

[0036] and the following judgment is made to update the speed feedforward of the position loop :

[0037] (5).

[0038] Further, the proportional term, the integral term, the differential term and the speed feedforward are summed to obtain a pre-saturation output of the position loop in the current period :

[0039] (6)

[0040] The pre-saturation output of the position loop is subjected to a limiting process to obtain a limiting output of the position loop :

[0041] (7)

[0042] wherein, , are the maximum and minimum limiting outputs of the position loop, respectively.

[0043] Further, the limiting output of the position loop is taken as a speed output reference to determine a real-time speed output, and the electric actuator is controlled in direction and commutation to execute

[0044] It is judged whether the speed output reference is non-negative, if yes, the electric actuator is controlled to rotate forward, and the real-time speed output keeps the speed output reference; otherwise, the electric actuator is controlled to rotate reversely, and the real-time speed output takes the absolute value of the speed output reference.

[0045] It is judged whether the rotating direction of the electric actuator in the current period is opposite to that in the last period, if yes, the commutation of the electric actuator is triggered, and all integral terms of the current loop are cleared.

[0046] Further, the commutation of the electric actuator is triggered to execute

[0047] When the electric actuator rotates forward, the commutation pointer adopts the reference position value detected by the Hall sensor;

[0048] When the electric actuator rotates reversely, the commutation pointer is the reference position value of the Hall sensor plus 3;

[0049] If the commutation pointer is greater than or equal to 6, the commutation pointer is corrected by subtracting 6.

[0050] Further, output the real-time target current as a real-time target current of the current loop at a real-time speed, limit the output of the current loop, and execute:

[0051] Generate a real-time current error according to the real-time target current and a real-time current feedback signal;

[0052] Perform PI processing on the real-time current error based on integral saturation optimization;

[0053] According to the PI processing result of the real-time current error, the limit output of the current loop is obtained.

[0054] Further, the determination of whether the electric actuator enters a steady state according to the real-time position error and the change of the real-time target position is executed.

[0055] Determine whether the absolute value of the real-time position error is less than a preset error threshold and whether the real-time target position of the current period is consistent with the real-time target position of the last period, if both conditions are met, the electric actuator enters a steady state; otherwise, the electric actuator does not enter a steady state.

[0056] Compared with the prior art, the present application can achieve at least one of the following beneficial effects:

[0057] The electric actuator control method based on integral saturation optimization and commutation differential enhancement provided by the present application solves the problems of integral saturation, commutation impact and steady-state jitter of traditional PID control through triple synergistic optimization, and specific explanations are as follows.

[0058] (1) Integral saturation adaptive suppression strategy (to solve the overshoot problem)

[0059] To solve the problem of excessive accumulation of the integral term when the position is locked or commutated, the technical concept of "stopping integration when the output is saturated, and allowing integration accumulation when the output is not saturated" is used. The output of the position loop and the current loop is detected in real time to determine whether the system enters a saturated state. When the output is not saturated, the integral term is normally accumulated according to the error. When the output is saturated, the integral term maintains the historical value and stops receiving new error accumulation to avoid redundant energy accumulation. The effect can be reflected in reducing the overshoot amount when the position is recalled or commutated, and shortening the recovery time of the saturated state.

[0060] (2) Commutation process differential smoothing enhancement strategy (to solve the commutation impact problem)

[0061] To suppress the differential disturbance when switching direction, optimization is made from the aspects of calculation method and commutation adaptation. On one hand, the differential item calculation logic is improved, the differential item is calculated based on the change rate of the proportional item (the difference between the current proportional item and the last period proportional item), instead of the traditional error instantaneous change rate, to filter high-frequency noise, realize commutation detection and dynamic adjustment. On the other hand, the commutation is judged by comparing the current and last time direction states, the current loop integral item is cleared immediately at the time of commutation, and the differential item calculation reference is reset, to avoid the differential spike caused by signal mutation. The torque impact and mechanical vibration at the time of commutation can be reduced, and the control smoothness is improved.

[0062] (3) Steady-state small error accurate locking strategy (solving the problem of steady-state jitter)

[0063] For the output fluctuation under small error, accurate locking is realized through threshold judgment: a preset position error threshold (corresponding to 1-2 times mechanical resolution) is set, when the error is less than the threshold and the target position is stable, it is determined that the system enters steady state; the current loop integral item is cleared in steady state, the position loop output is limited to approach zero, and the output adjustment caused by small disturbance is avoided. The position jitter is controlled within ±1 mechanical resolution, meeting the demand of high-precision holding.

[0064] (4) Three strategy collaborative mechanism

[0065] The cascade collaboration is realized through the three-closed-loop architecture of the position loop, the speed loop and the current loop: the position loop dominates the integral suppression and the differential smoothing, and outputs a stable speed instruction; since the actual working state of the steering engine does not involve speed control, the traditional speed closed loop is cancelled, and a speed feedforward is added after the position loop; the current loop undertakes the commutation integral clearing and steady-state optimization, and is converted into a smooth driving signal; the multi-stage closed loop dynamically adapts, and the rapid response and the anti-disturbance ability are considered.

[0066] To sum up, the steering engine control method based on integral saturation optimization and commutation differential enhancement provided by the application optimizes the single PID control used by the traditional steering engine, compared with the traditional method, can effectively suppress the integral saturation to reduce the overshoot, optimize the differential characteristics at the time of commutation to reduce the mechanical impact, and improve the steady-state locking precision, and is suitable for various types of steering engines, without changing the hardware, and is easy to implement in engineering.

[0067] The above technical solutions can be combined with each other in the application to realize more preferred combination solutions. Other features and advantages of the application will be set forth in the subsequent description, and some advantages can become apparent from the description, or can be understood by practicing the application. The objects and other advantages of the application can be realized and obtained by the content particularly pointed out in the specification and the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0068] The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and are not intended to limit the scope of the application, and together with the description serve to explain the principles of the application.

[0069] Figure 1 A flow chart of the rudder control method based on integral saturation optimization and commutation differential enhancement provided by the embodiment of the application is shown in the figure.

[0070] Figure 2 A flow chart of the rudder control method based on integral saturation optimization and commutation differential enhancement provided by the embodiment of the application is shown in the figure.

[0071] Figure 3 A flow chart of the position loop control module provided by the embodiment of the application is shown in the figure.

[0072] Figure 4 A flow chart of the direction and commutation control module provided by the embodiment of the application is shown in the figure.

[0073] Figure 5 A flow chart of the current loop control module provided by the embodiment of the application is shown in the figure. DETAILED DESCRIPTION

[0074] The preferred embodiments of the application are specifically described below in conjunction with the accompanying drawings, which form a part of this application, and together with the embodiments of the application serve to explain the principles of the application, but are not intended to limit the scope of the application.

[0075] The embodiment of the application provides a rudder control method based on integral saturation optimization and commutation differential enhancement, and a flow chart is shown in Figure 1 and Figure 2 The specific implementation steps of the method are described as follows.

[0076] Step S1: generating a real-time position error according to a real-time target position and a real-time position feedback signal of the electric rudder, and judging whether the electric rudder enters a steady state according to a change of the real-time position error and the real-time target position.

[0077] Step S2: if the electric rudder does not enter the steady state, performing amplitude limiting output on a position loop according to the real-time position error and a change rate of the real-time target position, to perform direction and commutation control and amplitude limiting output of a current loop on the electric rudder, and drive the electric rudder to run.

[0078] Step S3: if the electric rudder enters the steady state, controlling the output of the position loop to be 0, clearing the integral term of the current loop, and not running the electric rudder.

[0079] Specifically, in step S1, the following operations are performed.

[0080] Receiving a real-time target position (in the form of a position instruction) sent by the host computer, collecting a real-time position feedback signal of the electric rudder (an angle signal detected by an encoder, fed back through a position sensor); dividing the real-time position feedback signal by the number of pulses per channel of the encoder to obtain a real-time position feedback value; taking the difference between the real-time target position and the real-time position feedback value as a real-time position error .

[0081] (1)

[0082] wherein, is the real-time target position, is the real-time position feedback value.

[0083] (2)

[0084] wherein, is the number of pulses per channel of the encoder, used to convert the angle signal into a position quantity of the same dimension as the target position instruction, is a real-time position feedback signal of the electric rudder detected by the encoder.

[0085] Preferably, in step S1, whether the electric rudder enters a steady state is judged according to the real-time position error and the change of the real-time target position, and the following is performed:

[0086] whether the absolute value of the real-time position error is less than a preset error threshold, and whether the real-time target position of the current period is consistent with that of the last period, if both conditions are met, the electric rudder enters a steady state; otherwise, the electric rudder does not enter a steady state.

[0087] The corresponding discrimination formula can be expressed as:

[0088] (3)

[0089] wherein, represents the real-time target position of the last period, represents 2 times the pulse resolution of the encoder.

[0090] If the electric rudder enters a steady state, i.e. step S3 is performed, at this time, the output of the position loop is 0, the integral term of the current loop is cleared, and the electric rudder does not run, avoiding output fluctuations caused by small disturbances. It should be noted that ordinary PID will still continuously adjust due to noise or static error when the error is small, resulting in output jitter; and the present embodiment actively clears the integral term of the current loop and the output of the position loop through threshold judgment, and can achieve high-precision locking without jitter.

[0091] Next, the control mode when the electric rudder does not enter a steady state in step S2 is described as follows.

[0092] Step S21: Limit the output of the position loop based on the real-time position error and the change in the real-time target position.

[0093] Perform the following operations.

[0094] In the specific implementation process, the function of step S21 is completed by the position loop control module, and the flowchart of the position loop control module is attached. Figure 3 As shown.

[0095] Step S211: Perform PID processing on the real-time position error based on integral saturation optimization.

[0096] The specific processing procedure is described below.

[0097] (1) Proportional term

[0098] The proportional term of the position ring Represented as:

[0099] (4)

[0100] in, This is the scaling factor for the position ring.

[0101] (2) Integral term

[0102] Integral term of the position ring Represented as:

[0103] (5)

[0104] in, For the integral coefficients of the position loop, This is the integral term of the position loop from the previous cycle; , These are the limiting output and pre-saturation output of the position loop in the previous cycle, respectively.

[0105] In this embodiment, the integral term is dynamically adjusted based on whether the position loop output reaches a preset saturation threshold (i.e., whether the output exceeds the mechanical limit): if If so, it indicates that the output is not saturated, and the integral term is obtained by superimposing the current integral coefficient and the position error with the historical integral terms; if This indicates that the output is saturated, and the integral term remains unchanged from the historical integral term to avoid excessive accumulation.

[0106] In short, it is a logic that dynamically decides whether to continue to accumulate the integral term according to whether the output is continuously saturated: the integral is normally accumulated when the output is continuously saturated, and the integral accumulation is suspended (the historical value is kept) when the output deviates from saturation. While the ordinary PID integral term always accumulates the position error, it is easy to cause integral saturation; the embodiment stops the integral accumulation dynamically according to the output state, and suppresses saturation from the root.

[0107] (3) Derivative term

[0108] Derivative term of position loop is expressed as:

[0109] (6)

[0110] wherein, is the derivative coefficient of the position loop, is the proportional term of the position loop in the last period.

[0111] The existing way of calculating the derivative term directly depends on the error mutation, which is easy to amplify noise; the embodiment indirectly calculates the derivative term through the change rate of the proportional term, which can effectively smooth high-frequency disturbance, suppress noise, reduce the influence of the mutation of the feedback signal, is especially suitable for the signal jump scene during commutation, and can further optimize the efficiency during the debugging of the PID coefficient.

[0112] Step S212: calculating the speed feedforward of the position loop according to the change rate of the real-time target position.

[0113] Speed feedforward of position loop is expressed as:

[0114] (7)

[0115] wherein, is the target position in the last period, denotes the period.

[0116] And the following judgment is made to update the speed feedforward of the position loop :

[0117] (8)

[0118] The calculation method of the speed feedforward proposed in the embodiment can enhance the dynamic response speed on the one hand, and illustrates the correction logic of the speed feedforward in the position loop scene on the other hand, the core of which is to eliminate the “large difference in mathematical calculation” and retain the “real small change in physical motion”, to make boundary correction to the speed feedforward and avoid the mutation during direction switching.

[0119] In formula (8), 1 is a representative of the normalized range. In rudder control, position command usually adopts periodic coding (such as angle range 0°~360°, or normalized range 0~1, wherein “1” represents 360°). When the rudder jumps from 359° (corresponding to position command 0.997) to 1° (corresponding to position command 0.003), the mathematical position difference value is 0.003-0.997=-0.994, but the actual physical movement is only 2° (not 358° in reverse rotation). At this time, “1” as a correction value, the essence is to compensate the “period difference” of periodic jump: by adding 1 or subtracting 1, the “false large difference across the period” is corrected to “actual small angle change” (in the above example, -0.994+1=0.006, corresponding to actual 2° positive movement). “0.5” is the critical value for determining “whether it is a periodic jump”, which is set according to the physical movement limit of the rudder. Generally, it cannot reach such a large speed, so when the difference is equal to 0.5, it needs to be compensated by 1. When the rudder moves normally, the maximum speed may be only 0.1 period / control period (36° / control period), which is much smaller than 0.5, and does not need to be corrected; when the speed command is-0.8 (absolute value > 0.5), it is determined to be a jump across the period, and is corrected to 0.2 (corresponding to actual positive movement 72°) by +1, which meets the physical reality. While ordinary PID usually has no speed feedforward and only relies on error feedback for adjustment, the dynamic response is lagging; the present application applies control quantity in advance through target position change rate, improving the response speed.

[0120] Step S213: obtaining the amplitude-limited output of the position loop according to the proportional term, the integral term, the differential term and the speed feedforward of the position loop.

[0121] Summing the proportional term, the integral term, the differential term and the speed feedforward to obtain the position loop pre-saturation output of the current period

[0122] (9)

[0123] Amplitude-limiting the position loop pre-saturation output (limiting it within the preset maximum / minimum output range) to obtain the amplitude-limited output of the position loop

[0124] (10)

[0125] wherein, are the maximum and minimum amplitude-limited outputs of the position loop, respectively.

[0126] ​​​The rudder is restricted by mechanical structure (such as maximum angle, maximum torque) or driving circuit capability (such as maximum current), and the actual executable control amount has physical upper and lower limits. If the theoretical calculation exceeds this range, direct output will cause: mechanical component overload (such as gear jam, motor stall); driving circuit overcurrent (such as power tube damage); control logic failure (such as instructions cannot be executed, resulting in system instability). After limiting, it is always an effective instruction that the system can execute, taking into account control accuracy and hardware safety.

[0127] It should be noted that in this embodiment, the limiting logic and the "output saturation keeps the history value of the integral term" mentioned in the foregoing complement each other: limiting is a "hard constraint at the physical layer", which ensures that the output does not exceed the limit; and integral saturation suppression is a "flexible optimization at the algorithm layer", which avoids excessive accumulation of the integral term due to output exceeding the limit. Both of them together guarantee the stable operation of the system under the constraint condition.

[0128] Therefore, this embodiment innovates the traditional PID from four dimensions of saturation suppression of the integral term, anti-noise of the differential term, enhancement of the speed feedforward, and steady-state locking, and solves the core pain points in rudder control.

[0129] Step S22: determining the real-time speed output by taking the limited output of the position loop as the speed output reference, and controlling the direction and commutation of the electric rudder.

[0130] Specifically, the operation of step S22 is completed by a direction and commutation control module, and the flow of the direction and commutation control module is as shown in the accompanying Figure 4 drawings, and specific explanations are as follows.

[0131] Step S221: determining whether the speed output reference is non-negative, if yes, controlling the electric rudder to rotate forward, and keeping the real-time speed output as the speed output reference; otherwise, controlling the electric rudder to rotate reversely, and taking the absolute value of the speed output reference as the real-time speed output.

[0132] Specifically, the final output of the position loop is taken as the speed output reference: If the speed output reference is a non-negative value, it is determined that the electric rudder rotates forward, and the speed output keeps the reference value unchanged; if it is a negative value, it is determined that the rudder rotates reversely, and the speed output takes the absolute value of the reference value.

[0133] The real-time speed output is represented as:

[0134] (11)

[0135] If , the electric rudder is controlled to rotate forward, and the direction flag ; otherwise, , control the electric steering engine to rotate reversely, direction mark .

[0136] The traditional direction judgment needs to be calculated separately through the speed loop output or the position error direction. In this embodiment, the position loop output is directly used as the speed reference to realize the linkage determination of "position - speed - direction", which simplifies the signal transmission link of the multi-stage closed loop. The calculation delay of the independent speed loop is reduced, the response consistency of the direction determination and the position control is higher, and it is especially suitable for the steering field which needs to quickly commutate.

[0137] Step S222: judging whether the rotating direction of the electric steering engine in the current period is opposite to the rotating direction in the last period, if yes, triggering the commutation of the electric steering engine, and clearing all integral terms of the current loop.

[0138] In the specific implementation process, the commutation pointer (the electric motor rotates forward and reversely, and the commutation pointer is used to determine the current motion direction. The difference between the steering engine and the ordinary motor is that the commutation frequency will be high, and the direction will be changed frequently) is adjusted. When the electric steering engine rotates forward, the commutation pointer adopts the reference position value detected by the Hall sensor; when the electric steering engine rotates reversely, the commutation pointer is the reference position value of the Hall sensor plus 3 (adapted to the three-phase winding state when rotating reversely); if the commutation pointer is greater than or equal to 6, the commutation pointer is modified by subtracting 6 (to ensure that the pointer is within the effective range of 0-5, representing the Hall 6 phase). The traditional commutation pointer needs to be generated through complex Hall signal logic table lookup (such as judging according to the three-phase Hall state combination). The present application directly calculates the "direction + fixed offset (+3)" to adapt to the symmetry of the three-phase state when rotating reversely (the difference between the three-phase state when rotating forward and reversely is 3). The commutation pointer calculation does not need to look up the table, the logic is simple and real-time, and the possible delay or state misjudgment of the traditional table lookup method is avoided, which is especially suitable for high-speed commutation scenes.

[0139] In addition, the current rotating direction is compared with the rotating direction in the last control period (judged by the direction mark): if they are opposite (i.e. commutation occurs), the integral terms and the historical integral values of the current loop are immediately cleared to avoid the torque impact caused by the integral accumulation when commutation: , Finally, the current rotating direction is saved as the historical direction of the next period. Unlike the traditional PID which only adjusts the three-phase output state when commutation and ignores the accumulation effect of the integral term (the sudden error at the commutation moment will cause the abnormal growth of the integral term), the present embodiment binds the commutation detection and the integral clearing, and actively eliminates the redundant integral energy. The torque impact caused by the integral accumulation when commutation is avoided, the mechanical vibration and the wear of the transmission parts are reduced, and the instantaneous current is increased, so that the commutation smoothness is improved.

[0140] Step S23: Use the real-time speed output as the real-time target current of the current loop, and limit the output of the current loop; use the limited output of the current loop as the motor drive signal to drive the servo motor.

[0141] The specific implementation process of step S23 is carried out in the current loop control module, and the flowchart of the current loop control module is as follows: Figure 5 As shown.

[0142] Step S231: Generate real-time current error based on the real-time target current and the real-time current feedback signal.

[0143] First, the real-time target current of the current loop. .

[0144] Real-time acquisition of real-time current feedback signal from electric servo motor The difference between the target current command and the current feedback signal is calculated to obtain the real-time current error.

[0145] Real-time current error Represented as:

[0146] (12)

[0147] Step S232: Perform PI processing on the real-time current error based on integral saturation optimization.

[0148] (1) Proportional term

[0149] The proportional term of the current loop Represented as:

[0150] (13)

[0151] in, This represents the proportionality coefficient of the current loop.

[0152] (2) Integral term

[0153] Integral term of current loop for:

[0154] (14)

[0155] in, This represents the integral coefficient of the current loop. This represents the integral term of the current loop in the previous cycle; , These represent the current loop's limited output and pre-saturation output from the previous cycle, respectively.

[0156] In this embodiment, the current loop output is dynamically adjusted based on whether it reaches the saturation threshold: if If the output is not saturated, the integral term is the product of the current error and the current integral coefficient plus the history integral value; if If the output is saturated, the integral term remains the history integral value unchanged.

[0157] Step S233: According to the PI processing result of the real-time current error, the limiting output of the current loop is obtained.

[0158] The pre-saturation output of the current loop is represented as:

[0159] (15)

[0160] The pre-saturation output of the current loop is limited (limited to the preset maximum / minimum current range), and the limiting output of the current loop is obtained.

[0161] (16)

[0162] Wherein, 、 The maximum and minimum values of the current loop output limiting respectively correspond to the maximum and minimum drive currents allowed by the electric rudder.

[0163] The implementation process in step S3 is consistent with the anti-saturation strategy of the position loop, and the integral accumulation is dynamically stopped by the output state to form a multi-level anti-saturation cooperation of "position loop + current loop".

[0164] Those skilled in the art can understand that all or part of the processes of the above-mentioned embodiments can be completed by a computer program instructing related hardware, and the program can be stored in a computer readable storage medium. The computer readable storage medium is a disk, an optical disk, a read-only memory or a random access memory, etc.

[0165] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A rudder control method based on integral saturation optimization and commutation differential enhancement, characterized in that, The method comprises: generating a real-time position error according to a real-time target position of the electric rudder and a real-time position feedback signal; and determining whether the electric rudder enters a steady state according to the real-time position error and a change rate of the real-time target position; if the electric rudder does not enter the steady state, performing amplitude limiting output on a position loop according to the real-time position error and the change rate of the real-time target position, so as to perform direction and commutation control on the electric rudder and amplitude limiting output on a current loop, and drive the electric rudder to operate; if the electric rudder enters the steady state, controlling the output of the position loop to be 0, clearing the integral term of the current loop, and stopping the electric rudder from operating; if the electric rudder does not enter the steady state, performing: performing amplitude limiting output on the position loop according to the real-time position error and the change rate of the real-time target position; determining a real-time speed output by taking the amplitude limiting output of the position loop as a speed output reference, and performing direction and commutation control on the electric rudder; performing amplitude limiting output on the current loop by taking the real-time speed output as a real-time target current of the current loop, and taking the amplitude limiting output of the current loop as a motor driving signal to drive the rudder motor to operate; The proportional term of the position loop is represented as: (1) wherein, is a proportional coefficient of the position loop, denotes the real-time position error; Integral term of position loop is expressed as: (2) wherein is an integral coefficient of the position loop, is an integral term of the position loop of the previous cycle; , are, respectively, a clipped output and a pre-saturation output of the position loop of the previous cycle; The differential term of the position loop is represented as: (3) wherein, is a differential coefficient of the position loop, is a proportional term of the position loop of the previous cycle; Position loop velocity feed forward is represented as: (4) wherein, is the target position for the current time step, is the target position for the previous time step, and T denotes the period. And the following judgment, update the position ring speed feedforward : (5) The proportional term, the integral term, the differential term and the velocity feedforward are summed to obtain the position loop pre-saturation output of the current period : (6) The position loop pre-saturation output is limited to obtain a limited output of the position loop : (7) wherein, , are the maximum and minimum clipped outputs of the position loop, respectively.

2. The rudder control method based on integral saturation optimization and commutation differential enhancement according to claim 1, characterized in that, performing amplitude limiting output on the position loop according to the real-time position error and the change rate of the real-time target position, and executing: performing PID processing on the real-time position error based on integral saturation optimization; calculating a speed feedforward of the position loop according to the change rate of the real-time target position; obtaining the amplitude limiting output of the position loop according to a proportional term, an integral term and a differential term of the position loop and the speed feedforward.

3. The rudder control method based on integral saturation optimization and commutation differential enhancement according to claim 2, characterized in that, determining the real-time speed output by taking the amplitude limiting output of the position loop as the speed output reference, and performing direction and commutation control on the electric rudder, and executing: judging whether the speed output reference is non-negative, if yes, controlling the electric rudder to rotate in a forward direction, and keeping the real-time speed output as the speed output reference; otherwise, controlling the electric rudder to rotate in a reverse direction, and taking the absolute value of the speed output reference as the real-time speed output; judging whether the rotating direction of the electric rudder in a current period is opposite to that in a previous period, if yes, triggering commutation of the electric rudder, and clearing all integral terms of the current loop.

4. The rudder control method based on integral saturation optimization and commutation differential enhancement according to claim 3, characterized in that, the triggering of the commutation of the electric rudder, executing: when the electric rudder rotates in the forward direction, the commutation pointer adopts a reference position value detected by a Hall sensor; when the electric rudder rotates in the reverse direction, the commutation pointer is the reference position value of the Hall sensor plus 3; if the commutation pointer is greater than or equal to 6, the commutation pointer is corrected by subtracting 6.

5. The integrator saturation-based optimization and phase-differentiated augmentation-based steering engine control method according to claim 4, characterized by, performing amplitude limiting output on the current loop by taking the real-time speed output as the real-time target current of the current loop, and executing: generating a real-time current error according to the real-time target current and a real-time current feedback signal; performing PI processing on the real-time current error based on integral saturation optimization; obtaining the amplitude limiting output of the current loop according to the PI processing result of the real-time current error.

6. The integrator-saturation-based optimization and phase-differentiation- enhanced rudder control method according to any one of claims 1-5, characterized in that, the determining of whether the electric rudder enters the steady state according to the real-time position error and the change of the real-time target position, executing: judging whether the absolute value of the real-time position error is less than a preset error threshold, and whether the real-time target position in the current period is consistent with that in the previous period, if both are satisfied, the electric rudder enters the steady state; otherwise, the electric rudder does not enter the steady state.

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