A method for synchronously controlling multiple hydraulic actuators

Abstract

The present application relates to the technical field of hydraulic control, in particular to a kind of multi-hydraulic actuator synchronous control method.Mainly includes: step one: complete single-hydraulic actuator closed-loop controller design;Step two: design synchronization deviation compensation link;Step three: debug deviation compensation gain.The present application can flexibly, efficiently adjust the synchronization control precision of multi-hydraulic actuator by increasing synchronization deviation compensation link between closed-loop controller output and control element, and can be suitable for large quantities of hydraulic actuator synchronization control;The single-loop closed-loop control of each hydraulic actuator of the present application and synchronization deviation compensation control are relatively independent design, and synchronization precision is adjustable through deviation compensation gain, can effectively improve the flexibility and control accuracy of multi-hydraulic actuator synchronization control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic control, in particular to a multi-hydraulic actuator synchronous control method. BACKGROUND

[0002] For a hydraulic system provided with multiple sets of same hydraulic actuators and acting according to the same command, compared with the closed-loop control precision of a single actuator, the synchronization precision between the actuators becomes a more important index in some application scenarios. The system considering the hydraulic synchronization precision is called a hydraulic synchronization system.

[0003] The existing hydraulic synchronization system commonly uses the hydraulic synchronization control modes of master-slave control, equal control, cross-coupling control, adjacent cross-coupling control, etc., but it usually has problems such as insufficient synchronization precision, limited number of applicable hydraulic actuators, complex algorithm, etc., and the deviation compensation of the hydraulic synchronization system is generally applied to the command end of the closed-loop controller and is affected by the original closed-loop controller, so that the synchronization precision cannot be flexibly controlled. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a multi-hydraulic actuator synchronous control method, which can flexibly and efficiently adjust the synchronization control precision of multiple hydraulic actuators and is suitable for large quantities of hydraulic actuator synchronization control.

[0005] To solve the above technical problems, the technical solution adopted by the present application is:

[0006] A multi-hydraulic actuator synchronous control method, comprising the following steps:

[0007] S1, single-hydraulic actuator closed-loop controller design: without considering synchronization control, respectively performing single-loop output feedback closed-loop controller design of each hydraulic actuator;

[0008] S2, design of a synchronization deviation compensation link: according to the output feedback parameters of each hydraulic actuator and the average value thereof, calculating the synchronization deviation compensation of each hydraulic actuator;

[0009] S3, debug the deviation compensation gain: according to the current synchronization precision of the multiple hydraulic actuators, adjusting the value of the deviation compensation gain multiple times until the synchronization precision is within a preset range, then keeping the deviation compensation gain unchanged, and each hydraulic actuator executes the final control output according to the adjusted deviation compensation gain.

[0010] Further, in step S1, the closed-loop controller specifically adopts PID output feedback control.

[0011] Further, each hydraulic actuator adopts the same set of closed-loop controller design.

[0012] Further, the output feedback parameter of the i-th hydraulic actuator is denoted as yi, and the average value of the output feedback parameters is denoted as y m The specific implementation is as follows:

[0013]

[0014] In the formula, n is the number of hydraulic actuators.

[0015] Further, the synchronization deviation compensation amount of each hydraulic actuator is calculated as follows:

[0016] u ci = K (y m - y i )

[0017] In the formula, u ci is the synchronization deviation compensation amount of the i-th hydraulic actuator, and K is the deviation compensation gain.

[0018] Further, the closed-loop controller output u 0i of the i-th hydraulic actuator is limited in the effective input range of the control unit, then added to the corresponding synchronization deviation compensation amount u ci , and again limited in the effective input range of the control unit to obtain the final control output u i of the i-th hydraulic actuator.

[0019] Further, in step S3, the value of the deviation compensation gain is adjusted multiple times, specifically including:

[0020] 1) According to the final control output u i0 of each hydraulic actuator, the current synchronization accuracy T0 of the multi-hydraulic actuator system is calculated;

[0021] 2) If the current synchronization accuracy T0 of the system is lower than the preset value T, the deviation compensation gain K is adjusted for the first time, and the first adjusted deviation compensation gain K1 = 1.1 x K0, wherein K0 is the current deviation compensation gain of the system;

[0022] 3) Based on the first adjusted deviation compensation gain K1, the final control output u i1 of each hydraulic actuator is reacquired;

[0023] 4) According to the reacquired final control output u i1 of each hydraulic actuator, the synchronization accuracy T1 of the multi-hydraulic actuator system is calculated again;

[0024] 5) if the synchronization accuracy T1 of the system is still lower than the preset value T, the deviation compensation gain K1 is adjusted for the second time, and the deviation compensation gain K2 after the second adjustment = 1.1 x K1;

[0025] 6) repeat the above steps, if the synchronization accuracy Tn of the multi-hydraulic actuator system based on the deviation compensation gain K after the n th adjustment is not lower than the preset value T, control each hydraulic actuator to execute the current final control output u n , wherein n≥3. n in , wherein n≥3.

[0026] , wherein n≥3. n , and the final control output u of each hydraulic actuator is obtained based on the deviation compensation gain K after the n-1 th adjustment n-1 , and each hydraulic actuator is controlled to execute the current final control output u in-1 . in-1 .

[0027] Compared with the prior art, the present application has the following main advantages:

[0028] 1) by adding a synchronization deviation compensation link between the closed-loop controller output and the control element, the present application can flexibly and efficiently adjust the synchronization control accuracy of the multi-hydraulic actuator, and can be applied to large quantities of hydraulic actuator synchronization control.

[0029] 2) the single-loop closed-loop control and the synchronization deviation compensation control of each hydraulic actuator are relatively independently designed, the synchronization accuracy is adjustable through the deviation compensation gain, and the flexibility and control accuracy of the multi-hydraulic actuator synchronization control can be effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is the flow chart of the multi-hydraulic actuator synchronization control method in the embodiment of the present application;

[0031] Figure 2 is the principle block diagram of the multi-hydraulic actuator synchronization control method in the embodiment of the present application;

[0032] Figure 3 is the principle block diagram of the synchronization deviation compensation calculation in the embodiment of the present application;

[0033] Figure 4 is the control result schematic diagram when the control method of the present application is not used when the characteristics of the four reverse bucket actuator of a ship change;

[0034] Figure 5 ​The synchronous deviation schematic diagram when the control method of the present application is used and the control result schematic diagram when the control method of the present application is used and the deviation compensation gain is increased.

[0035] Figure 6 The synchronous deviation schematic diagram when the control method of the present application is used and the control result schematic diagram when the control method of the present application is used and the deviation compensation gain is increased.

[0036] Figure 7 The synchronous deviation schematic diagram when the control method of the present application is used and the control result schematic diagram when the control method of the present application is used and the deviation compensation gain is increased.

[0037] Figure 8 The synchronous deviation schematic diagram when the control method of the present application is used and the control result schematic diagram when the control method of the present application is used and the deviation compensation gain is increased.

[0038] Figure 9 The synchronous deviation schematic diagram when the control method of the present application is used and the control result schematic diagram when the control method of the present application is used and the deviation compensation gain is increased. DETAILED DESCRIPTION

[0039] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0040] It should be pointed out that, according to the needs of implementation, each step / component described in the present application can be split into more steps / components, or two or more steps / components or part of the operations of the steps / components can be combined into a new step / component to achieve the purpose of the present application.

[0041] Embodiment one, the present embodiment provides a multi-hydraulic actuator synchronization control method, as shown in Figures 1-3 The method mainly includes the following steps:

[0042] S1, single hydraulic actuator closed loop controller design: without considering synchronization control, respectively, the single loop output feedback closed loop controller design of each hydraulic actuator is carried out;

[0043] S2, design of synchronization deviation compensation link: according to the output feedback parameters of each hydraulic actuator and its average value, the synchronization deviation compensation amount of each hydraulic actuator is calculated;

[0044] S3, debugging deviation compensation gain: according to the current synchronization accuracy of the multiple hydraulic actuators, the value of the deviation compensation gain is adjusted multiple times until the synchronization accuracy is within the preset range, then the deviation compensation gain is kept unchanged, and each hydraulic actuator executes the final control output according to the adjusted deviation compensation gain.

[0045] Further, in step S1, the closed-loop controller specifically adopts PID output feedback control.

[0046] Further, each hydraulic actuator adopts the same set of closed-loop controller design.

[0047] Further, in step S2, the output feedback parameter of the i-th hydraulic actuator is denoted as yi, and the average value of the output feedback parameter is y m Specifically as follows:

[0048]

[0049] In the formula, n is the number of hydraulic actuators.

[0050] Further, the synchronization deviation compensation amount of each hydraulic actuator is calculated as follows:

[0051] u ci = K (y m -y i )

[0052] In the formula, u ci is the synchronization deviation compensation amount of the i-th hydraulic actuator, and K is the deviation compensation gain.

[0053] Further, the closed-loop controller output u 0i of the i-th hydraulic actuator is limited in amplitude according to the effective input range of the control unit, then added to the corresponding synchronization deviation compensation amount u ci , and again limited in amplitude according to the effective input range of the control unit, to obtain the final control output u i of the i-th hydraulic actuator.

[0054] Further, in step S3, the value of the deviation compensation gain is adjusted multiple times, specifically including:

[0055] 1) According to the final control output u i0 of each hydraulic actuator, the current synchronization accuracy T0 of the multiple hydraulic actuator system is calculated;

[0056] 2) If the current synchronization accuracy T0 of the system is lower than the preset value T, the deviation compensation gain K is adjusted for the first time, and the first adjusted deviation compensation gain K1=1.1×K0, wherein K0 is the current deviation compensation gain of the system;

[0057] 3) Based on the first adjusted deviation compensation gain K1, reacquire the final control output u of each hydraulic actuator i1 ;

[0058] 4) According to the reacquired final control output u of each hydraulic actuator i1 , calculate the synchronization accuracy T1 of the multi-hydraulic actuator system again;

[0059] 5) If the synchronization accuracy T1 of the system is still lower than the preset value T, adjust the deviation compensation gain K1 for the second time, and the second adjusted deviation compensation gain K2=1.1×K1;

[0060] 6) Repeat the above steps, if the calculated synchronization accuracy Tn of the multi-hydraulic actuator system based on the n-th adjusted deviation compensation gain Kn is not lower than the preset value T, control each hydraulic actuator to execute the current final control output u n , where n≥3. n in , where n≥3.

[0061] Wherein, if K n exceeds the preset deviation compensation gain threshold, based on the n-1-th adjusted deviation compensation gain K n-1 , acquire the final control output u of each hydraulic actuator in-1 , and control each hydraulic actuator to execute the current final control output u in-1 .

[0062] Embodiment two, the multi-hydraulic actuator synchronization control method provided by the embodiment comprises:

[0063] Step one: complete the single-hydraulic actuator closed-loop controller design;

[0064] Step two: design the synchronization deviation compensation link;

[0065] Step three: debug the deviation compensation gain.

[0066] Further, in step one, the method specifically comprises:

[0067] Without considering the synchronization control, complete the single-hydraulic actuator closed-loop controller design according to the conventional single-loop output feedback control method, and after debugging, meet the closed-loop control index requirements.

[0068] The closed-loop controller form can adopt but is not limited to the traditional PID, new type PID and other various output feedback control algorithms.

[0069] Each hydraulic actuator adopts the controller.

[0070] ​Furthermore, in step two, the method specifically includes:

[0071] Based on the feedback parameter y from each hydraulic actuator i Calculate the average value y m :

[0072]

[0073] In the formula, n represents the number of executing agencies.

[0074] Calculate the compensation amount u for each synchronization deviation ci :

[0075] u ci =K(y m -y i )

[0076] Equation K is the deviation compensation gain, initially set to a small value.

[0077] The output u of the closed-loop controller 0i After being limited according to the effective input range of the control unit, the synchronization deviation compensation amount u ci The summation, followed by limiting the effective input range of the control unit, yields the final control output u. i .

[0078] Furthermore, in step three, the method specifically includes:

[0079] Adjust the deviation compensation gain K according to the synchronization accuracy.

[0080] Increasing K can improve synchronization accuracy; however, an excessively large K value can also reduce system stability.

[0081] After several attempts, a suitable deviation compensation gain K value was obtained, and the design was completed.

[0082] This embodiment uses a ship as an example, which is equipped with four waterjet propulsion devices. The angle of the reverse bucket and the rudder angle are both driven by hydraulic cylinders, and the hydraulic system of each waterjet propulsion device is independent. Due to the compartmentalized layout of the hydraulic pump stations, the pipeline designs of the four hydraulic systems differ significantly.

[0083] The waterjet propulsion unit control unit is equipped with an amplifier board that drives the proportional valve, adjusting the hydraulic cylinder speed by controlling the valve opening. Angle closed-loop control is achieved by the propulsion remote control system, providing the necessary conditions for synchronous control.

[0084] The four systems use the same set of PID parameters for closed-loop angle control. Differentiated parameter settings are applied to the four systems to introduce synchronization deviations. The reverse bucket angle control response is as follows: Figure 4 As shown in the figure, the dashed lines represent angle commands. Figure 5The synchronization deviation of each pump is defined as the deviation of the angle of each pump from the average angle of the four pumps.

[0085] Therefore, the control method of the present application is adopted, and a synchronization deviation compensation link is added between the original PID controller and the control element, and the algorithm is as follows Figure 2 and Figure 3 . Figure 3 The limiting link after the original control output cannot be omitted, so as to avoid the case that the deviation compensation output is too small to play a role when the controller is seriously saturated. The control result of the reverse angle at this time is shown in Figure 6 . Figure 7 The synchronization deviation of each pump is defined as the deviation of the angle of each pump from the average angle of the four pumps.

[0086] On this basis, the deviation compensation gain K is increased, and the result is shown in Figure 8 and Figure 9 , and it can be seen that the maximum deviation is reduced to 0.54°.

[0087] It can be seen from the above technical solutions that the multi-hydraulic actuator synchronization control method provided by the above embodiments of the present application can be designed relatively independently for single-loop closed-loop control and synchronization deviation compensation control; the synchronization accuracy can be adjusted through the deviation compensation gain; and it is not limited by the number of hydraulic actuators.

[0088] Further, the parts not described in detail in the present application are the same as or realized by the prior art.

[0089] In summary:

[0090] 1. The present application can flexibly and efficiently adjust the synchronization control accuracy of the multi-hydraulic actuator by adding a synchronization deviation compensation link between the closed-loop controller output and the control element, and can be applied to large quantities of hydraulic actuator synchronization control.

[0091] 2. The single-loop closed-loop control of each hydraulic actuator and the synchronization deviation compensation control are designed relatively independently, the synchronization accuracy is adjustable through the deviation compensation gain, and the flexibility and control accuracy of the multi-hydraulic actuator synchronization control can be effectively improved.

[0092] Those skilled in the art will readily understand that the above description is only a preferred embodiment of the present application and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for synchronous control of multiple hydraulic actuators, characterized in that, Includes the following steps: S1, Design of a closed-loop controller for a single hydraulic actuator: Without considering synchronous control, design a single-loop output feedback closed-loop controller for each hydraulic actuator. S2, Design of synchronization deviation compensation mechanism: Calculate the synchronization deviation compensation amount of each hydraulic actuator based on the output feedback parameters and their average values. S3, Adjusting Deviation Compensation Gain: Based on the current synchronization accuracy of the multiple hydraulic actuators, adjust the value of the deviation compensation gain multiple times until the synchronization accuracy is within the preset range. Then, keep the deviation compensation gain unchanged. At the same time, each hydraulic actuator executes the final control output according to the adjusted deviation compensation gain. Wherein, the output feedback parameter of the i-th hydraulic actuator is denoted as yi, and the average value of the output feedback parameter is y. m Specifically as follows: In the formula, n is the number of hydraulic actuators; The synchronization deviation compensation amount of each hydraulic actuator is calculated as follows: In the formula, u ci Let K be the synchronization deviation compensation amount for the i-th hydraulic actuator, and K be the deviation compensation gain. The closed-loop controller output u for the i-th hydraulic actuator 0i After limiting the amplitude according to the effective input range of the control unit, it is then compared with the corresponding synchronization deviation compensation amount u. ci The sums are then limited again according to the effective input range of the control unit to obtain the final control output u of the i-th hydraulic actuator. i .

2. The method for synchronous control of multiple hydraulic actuators according to claim 1, characterized in that... In step S1, the closed-loop controller specifically adopts PID output feedback control.

3. The method for synchronous control of multiple hydraulic actuators according to claim 2, characterized in that, All hydraulic actuators use the same closed-loop controller design.

4. The method for synchronous control of multiple hydraulic actuators according to claim 1, characterized in that... In step S3, the multiple adjustments to the deviation compensation gain specifically include: 1) Based on the final control output u of each hydraulic actuator i0 Calculate the current synchronization accuracy T0 of the multi-hydraulic actuator system; 2) If the current synchronization accuracy T0 of the system is lower than the preset value T, the deviation compensation gain K is adjusted for the first time. The deviation compensation gain after the first adjustment is K1 = 1.1 × K0, where K0 is the current deviation compensation gain of the system. 3) Based on the deviation compensation gain K1 after the first adjustment, reacquire the final control output u of each hydraulic actuator. i1 ; 4) Based on the reacquired final control output u of each hydraulic actuator i1 Calculate the synchronization accuracy T1 of the multi-hydraulic actuator system again; 5) If the synchronization accuracy T1 of the system is still lower than the preset value T, the deviation compensation gain K1 is adjusted for the second time. The deviation compensation gain after the second adjustment is K2 = 1.1 × K1. 6) Repeat the above steps, based on the deviation compensation gain K after the nth adjustment. n The calculated synchronization accuracy T of the multi-hydraulic actuator system n If the value is not lower than the preset value T, then control each hydraulic actuator to execute the current final control output u. in , where n≥3.

5. The method for synchronous control of multiple hydraulic actuators according to claim 4, characterized in that, If K n If the deviation compensation gain exceeds the preset threshold, then the deviation compensation gain K is adjusted based on the (n-1)th time. n-1 Obtain the final control output u of each hydraulic actuator. in-1 And control each hydraulic actuator to execute the current final control output u in-1 .

Images