A hydraulic ship steering gear control method for implementing damping by using a four-layer network

Abstract

The present invention relates to a hydraulic ship steering gear control method for achieving damping by using a four-layer lead compensation correction network. It forms a closed-loop feedback by measuring the input steering angle command and the output steering angle of the steering gear through sensors, and measuring the valve-controlled cylinder piston displacement. At the same time, by constructing two series-connected lead hybrid compensation correction networks with similar structures, double damping signals of the steering angle error are obtained respectively. The valve-controlled cylinder piston displacement signal is input into the third lead hybrid compensation correction network to obtain an output signal, and the integral signal of the steering angle error and the valve-controlled cylinder piston displacement signal are combined to form a sliding mode. Then, the damping signal of the sliding mode signal is obtained through the fourth lead hybrid compensation correction network to improve the chattering problem in the dynamic operation of the steering gear, and the size fluctuation interference of the load is estimated by an adaptive method. Finally, the comprehensive control signal of the hydraulic steering gear is obtained to achieve the dynamic smooth and high-quality control of the ship hydraulic steering gear.

Description

Technical Field

[0001] The present invention relates to the field of industrial ship steering gear control, and more particularly, to a hydraulic ship steering gear control method for implementing damping by using a four-layer network. Background Art

[0002] In recent years, the shipbuilding industry in China has developed rapidly. The ship orders received each year account for 30% of the world market share, and the annual growth rate is over 50%. The steering gear is one of the core equipment of a ship, which is related to the safety and stability of ship navigation. Currently, most of the steering gears used in ships have problems such as low transmission efficiency, low steering angle control accuracy, and weak anti-load fluctuation ability. Compared with the steam drive and electric drive of the steering gear, the hydraulic drive has the advantages of large ship torque, strong anti-interference ability, sensitive response, and high energy consumption utilization rate. With the development of steering gear production technology, the performance of the steering gear is gradually improving. For example, the available power of the valve-controlled hydraulic steering gear is continuously increasing, and the minimum hydraulic pressure for driving the steering gear is continuously decreasing. Since the steering gear belongs to a non-linear system, and the load states of the ship under different environments, different speeds, and different working conditions are completely different, the traditional PID control is difficult to adapt to large-range load fluctuation changes. Often, the parameters with good dynamic performance under a certain working condition are not good in dynamic performance under another load environment. At the same time, in the complex electromagnetic interference environment of the ship, the ship steering gear has self-vibration or trembling phenomena, which will cause unnecessary wear to mechanical components. Based on the above background reasons, the present invention proposes a hydraulic ship steering gear control method for implementing damping by using a four-layer network, combined with interference adaptive estimation compensation, so that the entire steering gear can maintain high dynamic performance under different loads, and thus has high engineering application value.

[0003] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present invention, and thus may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0004] The purpose of the present invention is to provide a hydraulic ship steering gear control method for implementing damping by using a four-layer network, thereby overcoming the problems of steering gear jitter and weak anti-load fluctuation ability caused by defects in related technologies.

[0005] According to one aspect of the present invention, there is provided a hydraulic ship steering gear control method for implementing damping by using a four-layer network, including the following five steps:

[0006] Step S10: Install two angle sensors and a position sensor on the hydraulic ship steering gear, and use the angle sensors to measure the input steering angle command signal and the output steering gear angle signal respectively, where the input steering angle command signal is denoted as u 1 , and the output steering gear angle signal is denoted as u 2, a position sensor is used to measure the piston displacement signal of the valve-controlled cylinder, denoted as x V ;

[0007] Step S20: Compare the input rotation angle command signal and the output servo rotation angle signal of the hydraulic servo to obtain the servo rotation angle error signal; then design a first lead hybrid compensation correction network according to the servo rotation angle error signal, and select the initial value of the output signal of the first lead hybrid compensation correction network to be the same as the initial value of the error signal; and obtain the output growth signal of the first lead hybrid compensation correction network according to the error signal and the output signal of the first lead hybrid compensation correction network, then perform linear integral iteration to obtain the output signal of the first lead hybrid compensation correction network; then design a second lead hybrid compensation correction network according to the output growth signal of the first lead hybrid compensation correction network, and select the initial value of the output signal of the second lead hybrid compensation correction network to be the same as the initial value of the output growth signal of the first lead hybrid compensation correction network; obtain the output growth signal of the second lead hybrid compensation correction network according to the output growth signal of the first lead hybrid compensation correction network and the output signal of the second lead hybrid compensation correction network, then perform linear integral iteration to obtain the output signal of the second lead hybrid compensation correction network.

[0008] Step S30: Design a third lead hybrid compensation correction network according to the piston displacement signal of the valve-controlled cylinder and the servo rotation angle error signal, and design the initial value of the output signal of the third lead hybrid compensation correction network to be the same as the initial value of the piston displacement signal of the valve-controlled cylinder; then design the output growth signal of the third lead hybrid compensation correction network according to the piston displacement signal of the valve-controlled cylinder, the output signal of the third lead hybrid compensation correction network, and the servo rotation angle error signal, then perform linear integral iteration to obtain the output signal of the third lead hybrid compensation correction network; finally, non-linearly superimpose the output growth signal of the first lead hybrid compensation correction network and the output signal of the second lead hybrid compensation correction network on the output signal of the third lead hybrid compensation correction network; form the final hydraulic servo rotation angle comprehensive braking smoothing signal to provide smoothness for the control of the hydraulic servo.

[0009] Step S40: Integrate the shown steering gear angle error signal to obtain the integrated steering gear angle error signal. Then, synthesize the steering gear angle error signal, the hydraulic steering gear angle comprehensive braking smoothing signal, the error integrated signal, the valve-controlled cylinder piston displacement signal, and the output growth signal of the third lead hybrid compensation and correction network to obtain the hydraulic steering gear comprehensive sliding mode signal. Design a fourth lead hybrid compensation and correction network based on the hydraulic steering gear comprehensive sliding mode signal, set the initial value of the output signal of the fourth lead hybrid compensation and correction network to be the same as the initial value of the hydraulic steering gear comprehensive sliding mode signal, obtain the output growth signal of the fourth lead hybrid compensation and correction network by comparing the hydraulic steering gear comprehensive sliding mode signal with the output signal of the fourth lead hybrid compensation and correction network, and perform linear integral iteration to obtain the output signal of the fourth lead hybrid compensation and correction network.

[0010] Step S50: According to the hydraulic steering gear comprehensive sliding mode signal, adopt an adaptive method to separately design the constant estimation law of the steering gear load disturbance, the error estimation law of the steering gear load disturbance, the damping estimation law of the steering gear load disturbance, and the piston displacement estimation law of the steering gear load disturbance. Perform linear integral iteration to separately obtain the constant estimation signal of the steering gear load disturbance, the error estimation signal of the steering gear load disturbance, the damping estimation signal of the steering gear load disturbance, and the piston displacement estimation signal of the steering gear load disturbance. Synthesize them to obtain the total estimation signal of the steering gear load disturbance. Perform a non-linear transformation on the hydraulic steering gear comprehensive sliding mode signal to obtain the non-linear signal of the hydraulic steering gear comprehensive sliding mode, and then superimpose the hydraulic steering gear comprehensive sliding mode signal, the total estimation signal of the steering gear load disturbance, the output growth signal of the fourth lead hybrid compensation and correction network, the valve-controlled cylinder piston displacement signal, and the output signal of the fourth lead hybrid compensation and correction network to form the final hydraulic steering gear comprehensive control signal, which is sent to the input port of the operational amplifier circuit of the valve-controlled cylinder to control the piston movement of the valve-controlled cylinder, and drive the steering gear to generate an angle through the in-cylinder hydraulic transmission, thereby completing the control of the hydraulic steering gear.

[0011] In an exemplary embodiment of the present invention, compare the input steering gear angle command signal and the output steering gear angle signal of the hydraulic steering gear to obtain the steering gear angle error signal. Then, design a first lead hybrid compensation and correction network and a second lead hybrid compensation and correction network based on the steering gear angle error signal, and the output signals of the first lead hybrid compensation and correction network and the second lead hybrid compensation and correction network include:

[0012] e = u 1 -u 2 ;

[0013]

[0014]

[0015]

[0016]

[0017] where e is the steering gear angle error signal; ε 0 is a constant parameter signal; d e1 is the output growth signal of the first lead hybrid compensation correction network; d 1 is the output signal of the first lead hybrid compensation correction network; T is a constant integral parameter; d e2 is the output growth signal of the second lead hybrid compensation correction network; d 2 is the output signal of the second lead hybrid compensation correction network.

[0018] In an exemplary embodiment of the present invention, a third lead hybrid compensation correction network is designed according to the valve-controlled cylinder piston displacement signal and the steering gear angle error signal to obtain the output signal of the third lead hybrid compensation correction network; and the output signal of the third lead hybrid compensation correction network is nonlinearly superposed with the output growth signal of the first lead hybrid compensation correction network and the output signal of the second lead hybrid compensation correction network; The final hydraulic steering gear angle comprehensive braking smoothing signal includes:

[0019]

[0020]

[0021]

[0022] where d x1 is the output growth signal of the third lead hybrid compensation correction network; x 1 is the output signal of the third lead hybrid compensation correction network; d a is the hydraulic steering gear angle comprehensive braking smoothing signal.

[0023] In an exemplary embodiment of the present invention, the steering gear angle error signal is integrated to obtain the steering gear angle error integral signal; then the steering gear angle error signal, the hydraulic steering gear angle comprehensive braking smoothing signal, the error integral signal, the valve-controlled cylinder piston displacement signal, and the output growth signal of the third lead hybrid compensation correction network are integrated to obtain the hydraulic steering gear comprehensive sliding mode signal; and a fourth lead hybrid compensation correction network is designed according to the hydraulic steering gear comprehensive sliding mode signal to obtain the output signal of the fourth lead hybrid compensation correction network, including:

[0024] s 1 =∫edt;

[0025] s = e + c 1 d a + c2 s 1 +c 3 x V +c 4 d x1 ;

[0026]

[0027]

[0028] where s 1 is the integral signal of the steering gear angle error, and dt represents integration with respect to time; c 1 , c 2 , c 3 , c 4 , c 1 are constant parameters of the integrated sliding mode of the hydraulic steering gear; s is the integrated sliding mode signal of the hydraulic steering gear; ε 1 is a constant parameter; d s1 is the output growth signal of the fourth lead hybrid compensation correction network; d s is the output signal of the fourth lead hybrid compensation correction network.

[0029] In an exemplary embodiment of the present invention, according to the integrated sliding mode signal of the hydraulic steering gear, an adaptive method is used to separately design a constant estimation law for the steering gear load disturbance, an error estimation law for the steering gear load disturbance, a damping estimation law for the steering gear load disturbance, and a piston displacement estimation law for the steering gear load disturbance; and linear integral iteration is performed to obtain a constant estimation signal for the steering gear load disturbance, an error estimation signal for the steering gear load disturbance, a damping estimation signal for the steering gear load disturbance, and a piston displacement estimation signal for the steering gear load disturbance respectively; and a total estimation signal for the steering gear load disturbance is obtained through synthesis; a non-linear transformation is performed on the integrated sliding mode signal of the hydraulic steering gear to obtain a non-linear signal of the integrated sliding mode of the hydraulic steering gear, and then the integrated sliding mode signal of the hydraulic steering gear, the total estimation signal for the steering gear load disturbance, the output growth signal of the fourth lead hybrid compensation correction network, the valve-controlled cylinder piston displacement signal, and the output signal of the fourth lead hybrid compensation correction network are superimposed to form the final integrated control signal of the hydraulic steering gear, including:

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040] u = k 1 s + k 2 N + k 3 d s + k 4 x v + k 5 d s1 + M;

[0041] where ε 2 is a constant parameter, is a constant estimation signal of the servo load disturbance, k m1 is a constant parameter used to adjust the convergence rate of the constant estimation signal of the servo load disturbance, d m1 is the constant estimation law of the servo load disturbance; is the error estimation signal of the servo load disturbance, k m2 is a constant parameter used to adjust the convergence rate of the error estimation signal of the servo load disturbance, d m2 is the error estimation law of the servo load disturbance; is the damping estimation signal of the servo load disturbance, k m3 is a constant parameter used to adjust the convergence rate of the damping estimation signal of the servo load disturbance, d m3 is the damping estimation law of the servo load disturbance; is the piston displacement estimation signal of the servo load disturbance, k m4 is a constant parameter used to adjust the convergence rate of the piston displacement estimation signal of the servo load disturbance, d m4 is the piston displacement estimation law of the servo load disturbance; M is the total estimation signal of the servo load disturbance; N is the comprehensive sliding mode nonlinear signal of the hydraulic servo; k 1 、k 2 、k 3 、k 4 and k 5 are constant parameter signals; u is the comprehensive control signal of the hydraulic servo.

[0042] The output signal of the fourth lead mixed compensation correction network in the composition of the integrated control signal of the hydraulic steering gear has the same effect as the integrated sliding mode signal of the hydraulic steering gear, but the former has better smoothness; the output growth signal of the fourth lead mixed compensation correction network and the valve-controlled cylinder piston displacement signal are both for increasing the smoothness of the movement of the hydraulic steering gear and reducing high-frequency chattering; the introduction of the total estimated signal of the steering gear load disturbance is to compensate for the adverse effects brought by the load size fluctuation on the dynamic characteristics of the steering gear.

[0043] Beneficial effects

[0044] The present invention provides a hydraulic ship steering gear control method for realizing damping by using a four-layer network. Its main innovations are as follows: First, through four lead compensation correction networks with exactly the same structure, the damping signals of the steering gear angle error, the integrated sliding mode signal, and the smooth signal of the valve-controlled cylinder piston displacement signal are respectively obtained; its unified structure design brings simplicity to the design of the entire system. Second, the damping signal obtained through the lead compensation correction network improves the dynamic performance of the steering gear response and avoids the high-frequency chattering problem under the noise interference of the steering gear response. Third, the application of the lead compensation correction network avoids the measurement of the steering gear angular velocity signal and saves the cost of angular velocity measurement components, with better economy; Fourth, it avoids the problems of inconvenient installation and inaccurate measurement of angular velocity measurement components; Fifth, through the combination of the sliding mode and the adaptive method, adaptive compensation is carried out for the load change disturbance, so that the steering gear can maintain a high dynamic performance under different loads.

[0045] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present invention. Brief description of the drawings

[0046] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments in line with the present invention, and are used together with the specification to explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0047] Figure 1 is a flowchart of a dynamic method for a hydraulic ship steering gear control method for realizing damping by using a four-layer network provided by the present invention.

[0048] Figure 2 is a schematic diagram of a hydraulic ship steering gear system of the method provided by an embodiment of the present invention;

[0049] Figure 3 is the steering gear angle signal curve (unit: degree) of the method provided by an embodiment of the present invention;

[0050] Figure 4 is the valve-controlled cylinder piston displacement signal curve (unitless) of the method provided by the embodiments of the present invention;

[0051] Figure 5 is the steering gear angle error signal curve (unit: degree) of the method provided by the embodiments of the present invention;

[0052] Figure 6 is the output signal curve (unitless) of the second lead hybrid compensation correction network of the method provided by the embodiments of the present invention;

[0053] Figure 7 is the hydraulic steering gear angle comprehensive braking smoothing signal curve (unitless) of the method provided by the embodiments of the present invention;

[0054] Figure 8 is the output growth signal curve (unitless) of the fourth lead hybrid compensation correction network of the method provided by the embodiments of the present invention;

[0055] Figure 9 is the hydraulic steering gear comprehensive control signal curve (unitless) of the method provided by the embodiments of the present invention. Detailed implementation manners

[0056] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this invention will be more complete and comprehensive, and will fully convey the concept of the example embodiments to those skilled in the art. The features, structures, or characteristics described may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of the embodiments of the present invention. However, those skilled in the art will realize that the technical solutions of the present invention can be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. may be used. In other cases, well-known technical solutions are not shown or described in detail to avoid obscuring the various aspects of the present invention.

[0057] The present invention provides a hydraulic ship steering gear control method for damping by adopting a four-layer lead compensation correction network. It measures the input steering angle command and the output steering angle of the steering gear through sensors, and measures the valve-controlled cylinder piston displacement to form a closed-loop feedback. At the same time, by constructing two series-connected lead hybrid compensation correction networks with similar structures, double damping signals of the steering angle error are obtained respectively. The valve-controlled cylinder piston displacement signal is input into the third lead hybrid compensation correction network to obtain an output signal, and the integral signal of the steering angle error and the valve-controlled cylinder piston displacement signal are combined to form a sliding mode. Then, the damping signal of the sliding mode signal is obtained through the fourth lead hybrid compensation correction network to improve the chattering problem in the dynamic operation of the steering gear, and the size fluctuation interference of the load is estimated by an adaptive method. Finally, the comprehensive control signal of the hydraulic steering gear is obtained to achieve the dynamic smooth and high-quality control of the ship hydraulic steering gear.

[0058] Next, in conjunction with the accompanying drawings, a hydraulic ship steering gear control method for damping by adopting a four-layer network will be further explained and described. Refer to Figure 1 As shown, this hydraulic ship steering gear control method for damping by adopting a four-layer network includes the following steps:

[0059] Step S10, install two angle sensors and a position sensor on the hydraulic ship steering gear. Use the angle sensors to measure the input steering angle command signal and the output steering angle signal of the steering gear respectively, and use the position sensor to measure the valve-controlled cylinder piston displacement signal.

[0060] Specifically, the entire hydraulic ship steering gear system is as Figure 2 shown. The main components of the ship steering gear system mainly include an actuator, a drive system, and a control system. The actuator used in the present invention is a ball screw drive mechanism, which is installed at x p in the figure and has the advantages of small volume, light weight, and large rated load. The control system is located at C in the figure. The drive system adopts a valve-controlled cylinder link, which is composed of a spool at P s and a hydraulic cylinder at A p . Install an angle sensor on the hydraulic ship steering gear to measure the input steering angle command signal, denoted as u 1 ; install an angle sensor to measure the output steering angle signal of the steering gear, denoted as u 2 ; use a position sensor to measure the valve-controlled cylinder piston displacement signal, denoted as x V , as Figure 2 shown.

[0061] Step S20: Compare the input steering angle command signal and the output steering angle signal of the hydraulic steering gear to obtain the steering angle error signal of the steering gear; then design the first lead hybrid compensation correction network according to the steering angle error signal, and select the initial value of the output signal of the first lead hybrid compensation correction network to be the same as the initial value of the error signal; and obtain the output growth signal of the first lead hybrid compensation correction network according to the error signal and the output signal of the first lead hybrid compensation correction network, then perform linear integral iteration to obtain the output signal of the first lead hybrid compensation correction network; then design the second lead hybrid compensation correction network according to the output growth signal of the first lead hybrid compensation correction network, and select the initial value of the output signal of the second lead hybrid compensation correction network to be the same as the initial value of the output growth signal of the first lead hybrid compensation correction network; obtain the output growth signal of the second lead hybrid compensation correction network according to the output growth signal of the first lead hybrid compensation correction network and the output signal of the second lead hybrid compensation correction network, then perform linear integral iteration to obtain the output signal of the second lead hybrid compensation correction network.

[0062] Specifically, it can be decomposed into the following three steps. The first step: Compare the input steering angle command signal and the output steering angle signal of the hydraulic steering gear to obtain the steering angle error signal of the steering gear as follows:

[0063] e = u 1 - u 2 ;

[0064] where e is the steering angle error signal of the steering gear.

[0065] The second step: Design the first lead hybrid compensation correction network according to the steering angle error signal, and select the initial value of the output signal of the first lead hybrid compensation correction network to be the same as the initial value of the error signal; and obtain the output growth signal of the first lead hybrid compensation correction network according to the error signal and the output signal of the first lead hybrid compensation correction network, then perform linear integral iteration to obtain the output signal of the first lead hybrid compensation correction network as follows:

[0066]

[0067]

[0068] where ε 0 is a constant parameter signal; d e1 is the output growth signal of the first lead hybrid compensation correction network; d 1is the output signal of the first lead hybrid compensation correction network; T is a constant integral parameter; e(1) represents the first data of the servo angle error signal e, and e(n) is the nth data of the servo angle error signal e. The time interval between the data is the same as the constant integral parameter T. The discrete data definitions of other subsequent variables are the same as this and will not be repeated here.

[0069] Step 3: Design a second lead hybrid compensation correction network according to the output growth signal of the first lead hybrid compensation correction network, and select the initial value of the output signal of the second lead hybrid compensation correction network to be the same as the initial value of the output growth signal of the first lead hybrid compensation correction network; obtain the output growth signal of the second lead hybrid compensation correction network according to the output growth signal of the first lead hybrid compensation correction network and the output signal of the second lead hybrid compensation correction network, and then perform linear integral iteration to obtain the output signal of the second lead hybrid compensation correction network as follows:

[0070]

[0071]

[0072] where d e2 is the output growth signal of the second lead hybrid compensation correction network; d 2 is the output signal of the second lead hybrid compensation correction network;

[0073] Step S30: Design a third lead hybrid compensation correction network according to the valve-controlled cylinder piston displacement signal and the servo angle error signal, and design the initial value of the output signal of the third lead hybrid compensation correction network to be the same as the initial value of the valve-controlled cylinder piston displacement signal; then design the output growth signal of the third lead hybrid compensation correction network according to the valve-controlled cylinder piston displacement signal, the output signal of the third lead hybrid compensation correction network, and the servo angle error signal, and then perform linear integral iteration to obtain the output signal of the third lead hybrid compensation correction network; finally, non-linearly superimpose the output growth signal of the first lead hybrid compensation correction network and the output signal of the second lead hybrid compensation correction network with the output signal of the third lead hybrid compensation correction network; form the final hydraulic servo angle comprehensive braking smoothing signal to provide smoothness for the control of the hydraulic servo.

[0074] Specifically, first design a third lead hybrid compensation correction network according to the valve-controlled cylinder piston displacement signal and the servo angle error signal, and design the initial value of the output signal of the third lead hybrid compensation correction network to be the same as the initial value of the valve-controlled cylinder piston displacement signal; then design the output growth signal of the third lead hybrid compensation correction network as follows according to the valve-controlled cylinder piston displacement signal, the output signal of the third lead hybrid compensation correction network, and the servo angle error signal:

[0075]

[0076] where d x1 is the output growth signal of the third lead hybrid compensation correction network.

[0077] Secondly, linear integral iteration is performed on the output growth signal of the third lead hybrid compensation correction network to obtain the output signal of the third lead hybrid compensation correction network as follows:

[0078]

[0079] where x 1 is the output signal of the third lead hybrid compensation correction network.

[0080] Finally, the output signal of the third lead hybrid compensation correction network is non-linearly superimposed with the output growth signal of the first lead hybrid compensation correction network and the output signal of the second lead hybrid compensation correction network; to form the final hydraulic steering gear angle comprehensive braking smoothing signal as follows:

[0081]

[0082] d a is the hydraulic steering gear angle comprehensive braking smoothing signal; where the output growth signal of the first lead hybrid compensation correction network and the output signal of the second lead hybrid compensation correction network are first superimposed, and the superimposition weight depends on the magnitude of the steering gear angle error signal and the difference between the output growth signal of the first lead hybrid compensation correction network and the output signal of the second lead hybrid compensation correction network.

[0083] Step S40, integrate according to the shown steering gear angle error signal to obtain the steering gear angle error integral signal; then synthesize the steering gear angle error signal, the hydraulic steering gear angle comprehensive braking smoothing signal, the error integral signal, the valve-controlled cylinder piston displacement signal, and the output growth signal of the third lead hybrid compensation correction network to obtain the hydraulic steering gear comprehensive sliding mode signal; and design a fourth lead hybrid compensation correction network according to the hydraulic steering gear comprehensive sliding mode signal, set the initial value of the output signal of the fourth lead hybrid compensation correction network to be the same as the initial value of the hydraulic steering gear comprehensive sliding mode signal, and obtain the output growth signal of the fourth lead hybrid compensation correction network by comparing the hydraulic steering gear comprehensive sliding mode signal with the output signal of the fourth lead hybrid compensation correction network, and perform linear integral iteration to obtain the output signal of the fourth lead hybrid compensation correction network.

[0084] Specifically, it can be decomposed into the following three small steps. First, integrate according to the shown steering gear angle error signal to obtain the steering gear angle error integral signal as follows:

[0085] s 1 = ∫edt;

[0086] where s 1 is the integral signal of the steering gear angle error, and dt represents the integration over time.

[0087] Secondly, the steering gear angle error signal, the hydraulic steering gear angle comprehensive braking smoothing signal, the error integral signal, the valve-controlled cylinder piston displacement signal, and the output growth signal of the third lead hybrid compensation correction network are synthesized to obtain the following hydraulic steering gear comprehensive sliding mode signal:

[0088] s = e + c 1 d a + c 2 s 1 + c 3 x V + c 4 d x1 ;

[0089] where c 1 , c 2 , c 3 , c 4 are the constant parameters of the hydraulic steering gear comprehensive sliding mode, and s is the hydraulic steering gear comprehensive sliding mode signal.

[0090] Finally, a fourth lead hybrid compensation correction network is designed according to the hydraulic steering gear comprehensive sliding mode signal, and the initial value of the output signal of the fourth lead hybrid compensation correction network is set to be the same as the initial value of the hydraulic steering gear comprehensive sliding mode signal. The output growth signal of the fourth lead hybrid compensation correction network is obtained by comparing the hydraulic steering gear comprehensive sliding mode signal with the output signal of the fourth lead hybrid compensation correction network, and the output signal of the fourth lead hybrid compensation correction network is obtained through linear integral iteration as follows:

[0091]

[0092]

[0093] where ε 1 is a constant parameter; d s1 is the output growth signal of the fourth lead hybrid compensation correction network; d s is the output signal of the fourth lead hybrid compensation correction network. The output growth signal of the fourth lead hybrid compensation correction network is mainly used to provide a sliding mode damping signal for the control of the hydraulic steering gear to suppress the chatter of the steering gear.

[0094] Step S50: According to the hydraulic servo integrated sliding mode signal, an adaptive method is adopted to respectively design the constant value estimation law of the servo load disturbance, the error estimation law of the servo load disturbance, the damping estimation law of the servo load disturbance, and the piston displacement estimation law of the servo load disturbance; and linear integral iteration is carried out to respectively obtain the constant value estimation signal of the servo load disturbance, the error estimation signal of the servo load disturbance, the damping estimation signal of the servo load disturbance, and the piston displacement estimation signal of the servo load disturbance; and then they are synthesized to obtain the total estimation signal of the servo load disturbance, and then the hydraulic servo integrated sliding mode signal, the hydraulic servo integrated sliding mode nonlinear signal, the output growth signal of the fourth lead hybrid compensation correction network, the valve-controlled cylinder piston displacement signal, and the output signal of the fourth lead hybrid compensation correction network are superimposed to form the final hydraulic servo integrated control signal.

[0095] Specifically, it can be decomposed into the following eight small steps. The first step: According to the hydraulic servo integrated sliding mode signal, an adaptive method is adopted to design the constant value estimation law of the servo load disturbance; and linear integral iteration is carried out to obtain the constant value estimation signal of the servo load disturbance as follows;

[0096]

[0097]

[0098] where ε 2 is a constant parameter, is the constant value estimation signal of the servo load disturbance, k m1 is a constant parameter used to adjust the convergence rate of the constant value estimation signal of the servo load disturbance, and d m1 is the constant value estimation law of the servo load disturbance.

[0099] The second step: According to the hydraulic servo integrated sliding mode signal, an adaptive method is adopted to design the error estimation law of the servo load disturbance; and linear integral iteration is carried out to obtain the error estimation signal of the servo load disturbance as follows;

[0100]

[0101]

[0102] where is the error estimation signal of the servo load disturbance, k m2 is a constant parameter used to adjust the convergence rate of the error estimation signal of the servo load disturbance, and d m2 is the error estimation law of the servo load disturbance.

[0103] The third step: According to the hydraulic servo integrated sliding mode signal, an adaptive method is adopted to design the damping estimation law of the servo load disturbance; and linear integral iteration is carried out to obtain the damping estimation signal of the servo load disturbance as follows:

[0104]

[0105]

[0106] where is the servo load disturbance damping estimation signal, and k m3 is a constant parameter used to adjust the convergence rate of the servo load disturbance damping estimation signal, and d m3 is the servo load disturbance damping estimation law.

[0107] Step 4: According to the hydraulic servo integrated sliding mode signal, an adaptive method is used to design the servo load disturbance piston displacement estimation law; and linear integral iteration is performed to obtain the servo load disturbance piston displacement estimation signal as follows:

[0108]

[0109]

[0110] where is the servo load disturbance piston displacement estimation signal, and k m4 is a constant parameter used to adjust the convergence rate of the servo load disturbance piston displacement estimation signal, and d m4 is the servo load disturbance piston displacement estimation law.

[0111] Step 5: The above four estimation signals are synthesized to obtain the total servo load disturbance estimation signal as follows:

[0112]

[0113] where M is the total servo load disturbance estimation signal.

[0114] Step 6: The hydraulic servo integrated sliding mode signal is nonlinearly transformed to obtain the hydraulic servo integrated sliding mode nonlinear signal as follows:

[0115]

[0116] where N is the hydraulic servo integrated sliding mode nonlinear signal.

[0117] Step 7: The hydraulic servo integrated sliding mode nonlinear signal is used to superimpose the hydraulic servo integrated sliding mode signal, the hydraulic servo integrated sliding mode nonlinear signal, the output growth signal of the fourth lead hybrid compensation correction network, the valve-controlled cylinder piston displacement signal, and the output signal of the fourth lead hybrid compensation correction network to form the final hydraulic servo integrated control signal as follows:

[0118] u = k 1 s + k 2N + k 3 d s + k 4 x v + k 5 d s1 + M;

[0119] where k 1 , k 2 , k 3 , k 4 and k 5 are constant parameter signals; u is the comprehensive control signal of the hydraulic steering gear. The output signal of the fourth lead mixed compensation correction network in the composition of this signal has the same effect as the comprehensive sliding mode signal of the hydraulic steering gear, but the former has better smoothness; the output growth signal of the fourth lead mixed compensation correction network and the valve-controlled cylinder piston displacement signal are both for increasing the smoothness of the hydraulic steering gear movement and reducing high-frequency chattering; the introduction of the total estimated signal of the steering gear load disturbance is to compensate for the adverse effects of the load size fluctuation on the dynamic characteristics of the steering gear.

[0120] In the eighth step, the comprehensive control signal of the hydraulic steering gear will be sent to the input port of the operational amplifier circuit of the valve-controlled cylinder to control the piston movement of the valve-controlled cylinder, and drive the steering gear to generate an angle through the hydraulic transmission in the cylinder, thus completing the control of the hydraulic steering gear.

[0121] Case implementation and analysis of computer simulation results

[0122] In step S10, set the input command signal to 15 degrees, and the steering gear angle signal measured by the angle sensor is as Figure 3 shown; the valve-controlled cylinder piston displacement signal measured by the position sensor is as Figure 4 shown.

[0123] In step S20, select ε 0 = 0.05, T = 0.001, and the steering gear angle error signal is as Figure 5 shown, and the output signal of the second lead mixed compensation correction network is as Figure 6 shown.

[0124] In step S30, the comprehensive braking smooth signal of the hydraulic steering gear angle is as Figure 7 shown.

[0125] In step S40, select c 1 = 0.5, c 2 = 1.3, c 3 = 0.3, c 4 = 0.3, ε 1 = 0.25, and the output growth signal of the fourth lead mixed compensation correction network is as Figure 8 shown.

[0126] In step S50, ε is selected 2 = 0.5, k m1 = 0.001, k m2 = 0.002, k m3 = 0.001, k m4 = 0.002, k 1 = 3500, k 2 = 1200, k 3 = 250, k 4 = 920 and k 5 = 380; the final comprehensive control signal of the hydraulic steering gear is obtained as Figure 9 shown.

[0127] It can be seen from Figure 3 that the whole system can complete the tracking of the input signal of 15 degrees within 2 s. This is mainly due to the relatively large gain of the whole control. If high-gain feedback control is not adopted, the response of the system will be very slow. And Figure 5 it can be seen that the steering gear angle error can converge to 0 within 2 s, and its control accuracy is very high; it can be seen from Figure 7 that the comprehensive braking smoothing signal of the hydraulic steering gear angle is relatively large in the initial stage and immediately becomes negative after about 0.2 s. Its whole process mainly plays the role of braking and smoothing; it can be seen from Figure 9 that the final comprehensive control signal of the hydraulic steering gear is also relatively large, but when the control is completed, its comprehensive control signal converges to the zero position. From the above cases, it can be shown that the method provided by the present invention is effective and has good engineering application value.

Claims

1. A hydraulic ship steering gear control method for achieving damping by using a four-layer network, characterized in that, it includes the following steps: Step S10, install two angle sensors and one position sensor on a hydraulic ship steering gear. Use the angle sensors to measure the input steering angle command signal and the output steering gear angle signal respectively, where the input steering angle command signal is denoted as u 1 , and the output steering gear angle signal is denoted as u 2 . Use the position sensor to measure the valve-controlled cylinder piston displacement signal, denoted as x V ; Step S20: Compare the input rotation angle command signal of the hydraulic steering gear with the output steering gear rotation angle signal to obtain a steering gear rotation angle error signal; then design a first lead hybrid compensation correction network according to the steering gear rotation angle error signal, and select the initial value of the output signal of the first lead hybrid compensation correction network to be the same as the initial value of the error signal; and obtain the output growth signal of the first lead hybrid compensation correction network according to the error signal and the output signal of the first lead hybrid compensation correction network, then perform linear integral iteration to obtain the output signal of the first lead hybrid compensation correction network; then design a second lead hybrid compensation correction network according to the output growth signal of the first lead hybrid compensation correction network, and select the initial value of the output signal of the second lead hybrid compensation correction network to be the same as the initial value of the output growth signal of the first lead hybrid compensation correction network; obtain the output growth signal of the second lead hybrid compensation correction network according to the output growth signal of the first lead hybrid compensation correction network and the output signal of the second lead hybrid compensation correction network, then perform linear integral iteration to obtain the output signal of the second lead hybrid compensation correction network as follows: e = u 1 -u 2 ; where e is the steering gear angle error signal; ε 0 is a constant parameter signal; d e1 is the output growth signal of the first lead hybrid compensation correction network; d 1 is the output signal of the first lead hybrid compensation correction network; T is a constant integral parameter; d e2 is the output growth signal of the second lead hybrid compensation correction network; d 2 is the output signal of the second lead hybrid compensation correction network; Step S30: Design a third lead hybrid compensation correction network according to the valve-controlled cylinder piston displacement signal and the steering gear rotation angle error signal, and design the initial value of the output signal of the third lead hybrid compensation correction network to be the same as the initial value of the valve-controlled cylinder piston displacement signal; then obtain the output growth signal of the third lead hybrid compensation correction network according to the valve-controlled cylinder piston displacement signal, the output signal of the third lead hybrid compensation correction network, and the steering gear rotation angle error signal, then perform linear integral iteration to obtain the output signal of the third lead hybrid compensation correction network; finally, non-linearly superimpose the output growth signal of the first lead hybrid compensation correction network and the output signal of the second lead hybrid compensation correction network with the output signal of the third lead hybrid compensation correction network; form the final hydraulic steering gear rotation angle comprehensive braking smoothing signal to provide smoothness for the control of the hydraulic steering gear as follows: where d x1 is the output growth signal of the third lead hybrid compensation correction network; x 1 is the output signal of the third lead hybrid compensation correction network; d a is the hydraulic steering gear angle comprehensive braking smoothing signal; during the superposition process, the output growth signal of the first lead hybrid compensation correction network and the output signal of the second lead hybrid compensation correction network are first superimposed, and the superimposition weight depends on the magnitude of the steering gear angle error signal and the difference between the output growth signal of the first lead hybrid compensation correction network and the output signal of the second lead hybrid compensation correction network; Step S40: Integrate the shown steering gear rotation angle error signal to obtain a steering gear rotation angle error integral signal; then synthesize the steering gear rotation angle error signal, the hydraulic steering gear rotation angle comprehensive braking smoothing signal, the error integral signal, the valve-controlled cylinder piston displacement signal, and the output growth signal of the third lead hybrid compensation correction network to obtain a hydraulic steering gear comprehensive sliding mode signal; and design a fourth lead hybrid compensation correction network according to the hydraulic steering gear comprehensive sliding mode signal, and set the initial value of the output signal of the fourth lead hybrid compensation correction network to be the same as the initial value of the hydraulic steering gear comprehensive sliding mode signal, and obtain the output growth signal of the fourth lead hybrid compensation correction network by comparing the hydraulic steering gear comprehensive sliding mode signal with the output signal of the fourth lead hybrid compensation correction network, and perform linear integral iteration to obtain the output signal of the fourth lead hybrid compensation correction network as follows: s 1 = ∫edt; s = e + c 1 d a + c 2 s 1 + c 3 x V + c 4 d x1 ; where s 1 is the integral signal of the steering gear angle error, and dt represents integration over time; c 1 , c 2 , c 3 , c 4 are the constant parameters of the integrated sliding mode of the hydraulic steering gear; s is the integrated sliding mode signal of the hydraulic steering gear; ε 1 is a constant parameter; d s1 is the output growth signal of the fourth lead hybrid compensation correction network; d s is the output signal of the fourth lead hybrid compensation correction network. The output growth signal of the fourth lead hybrid compensation correction network is mainly used to provide a sliding mode damping signal for the control of the hydraulic steering gear to suppress the chattering of the steering gear; Step S50: According to the comprehensive sliding mode signal of the hydraulic steering gear, using an adaptive method, design the constant value estimation law of the steering gear load disturbance, the error estimation law of the steering gear load disturbance, the damping estimation law of the steering gear load disturbance, and the piston displacement estimation law of the steering gear load disturbance respectively; And perform linear integral iteration to obtain the constant value estimation signal of the steering gear load disturbance, the error estimation signal of the steering gear load disturbance, the damping estimation signal of the steering gear load disturbance, and the piston displacement estimation signal of the steering gear load disturbance respectively; And perform synthesis to obtain the total estimation signal of the steering gear load disturbance; perform a non-linear transformation on the comprehensive sliding mode signal of the hydraulic steering gear to obtain the non-linear signal of the comprehensive sliding mode of the hydraulic steering gear, and then superimpose the comprehensive sliding mode signal of the hydraulic steering gear, the total estimation signal of the steering gear load disturbance, the output growth signal of the fourth lead hybrid compensation correction network, the piston displacement signal of the valve-controlled cylinder, and the output signal of the fourth lead hybrid compensation correction network to form the final comprehensive control signal of the hydraulic steering gear, and transmit it to the input port of the operational amplifier circuit of the valve-controlled cylinder to control the piston movement of the valve-controlled cylinder, and drive the steering gear to generate an angle through the hydraulic transmission in the cylinder, so as to complete the control of the hydraulic steering gear as follows: u = k 1 s + k 2 N + k 3 d s + k 4 x v + k 5 d s1 + M; where ε 2 is a constant parameter, is a constant estimation signal of the servo load disturbance, k m1 is a constant parameter used to adjust the convergence rate of the constant estimation signal of the servo load disturbance, d m1 is the constant estimation law of the servo load disturbance; is the error estimation signal of the servo load disturbance, k m2 is a constant parameter used to adjust the convergence rate of the error estimation signal of the servo load disturbance, d m2 is the error estimation law of the servo load disturbance; is the damping estimation signal of the servo load disturbance, k m3 is a constant parameter used to adjust the convergence rate of the damping estimation signal of the servo load disturbance, d m3 is the damping estimation law of the servo load disturbance; is the piston displacement estimation signal of the servo load disturbance, k m4 is a constant parameter used to adjust the convergence rate of the piston displacement estimation signal of the servo load disturbance, d m4 is the piston displacement estimation law of the servo load disturbance; M is the total estimation signal of the servo load disturbance; N is the integrated sliding mode nonlinear signal of the hydraulic servo; k 1 、k 2 、k 3 、k 4 and k 5 are constant parameter signals; u is the integrated control signal of the hydraulic servo. The output signal of the fourth lead hybrid compensation correction network in the composition of this signal has the same effect as the integrated sliding mode signal of the hydraulic servo, but the former has better smoothness; the output growth signal of the fourth lead hybrid compensation correction network and the valve-controlled cylinder piston displacement signal are both for increasing the smoothness of the hydraulic servo movement and reducing high-frequency chattering; the introduction of the total estimation signal of the servo load disturbance is to compensate for the adverse effects brought by the fluctuation of the load size on the dynamic characteristics of the servo.

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