Synchronous control method for multiple hydraulic actuating mechanisms

Abstract

The invention relates to the technical field of hydraulic control, in particular to a synchronous control method for multiple hydraulic executing mechanisms. The method mainly comprises the following steps: step 1, completing the design of a closed-loop controller of a single hydraulic actuating mechanism; 2, designing a synchronization deviation compensation link; and step 3, debugging the deviation compensation gain. The synchronous deviation compensation link is added between the output of the closed-loop controller and the control element, so that the synchronous control precision of the multiple hydraulic executing mechanisms can be flexibly and efficiently adjusted, and the method can be suitable for synchronous control of the hydraulic executing mechanisms on a large scale; single-loop closed-loop control and synchronous deviation compensation control of each hydraulic actuating mechanism are relatively independently designed, the synchronous precision can be adjusted through deviation compensation gain, and the flexibility and the control accuracy of synchronous control of the multiple hydraulic actuating mechanisms can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic control, and in particular to a synchronous control method for multiple hydraulic actuators. Background Art

[0002] For a hydraulic system with multiple sets of identical hydraulic actuators that act according to the same command, the synchronization accuracy between the actuators becomes a more important indicator of the system in certain application scenarios than the closed-loop control accuracy of a single actuator. A system that takes hydraulic synchronization accuracy into consideration is called a hydraulic synchronization system.

[0003] The hydraulic synchronization system of the prior art commonly uses hydraulic synchronization control methods such as master-slave control, equivalent control, cross-coupling control, adjacent cross-coupling control, etc., but they usually have problems such as insufficient synchronization accuracy, or a limited number of applicable hydraulic actuators, or complex algorithms. In addition, the deviation compensation amount of the hydraulic synchronization system generally acts on the command end of the closed-loop controller and is affected by the original closed-loop controller, and the synchronization accuracy cannot be flexibly controlled. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for synchronous control of multiple hydraulic actuators, which can flexibly and efficiently adjust the synchronous control accuracy of multiple hydraulic actuators and is suitable for synchronous control of a large number of hydraulic actuators.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A method for synchronously controlling multiple hydraulic actuators comprises the following steps:

[0007] S1, design of closed-loop controller for single hydraulic actuator: without considering synchronous control, design of single-loop output feedback closed-loop controller for each hydraulic actuator is performed separately;

[0008] S2, design the synchronization deviation compensation link: calculate the synchronization deviation compensation amount of each hydraulic actuator according to the output feedback parameters of each hydraulic actuator and their average values;

[0009] S3, debugging the 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, and the deviation compensation gain is kept unchanged. At the same time, each hydraulic actuator executes the final control output according to the adjusted deviation compensation gain.

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

[0011] Furthermore, each of the hydraulic actuators adopts the same closed-loop controller design.

[0012] Furthermore, in step S2, the output feedback parameter of the i-th hydraulic actuator is recorded as yi, and the average value of the output feedback parameter y m The details are as follows:

[0013]

[0014] Where n is the number of hydraulic actuators.

[0015] Furthermore, 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 synchronous deviation compensation of the i-th hydraulic actuator, and K is the deviation compensation gain.

[0018] Furthermore, the closed-loop controller output u of the i-th hydraulic actuator is 0i After limiting the effective input range of the control unit, the corresponding synchronous deviation compensation value u ci After adding and limiting according to the effective input range of the control unit again, the final control output u of the i-th hydraulic actuator is obtained. i .

[0019] Furthermore, in step S3, the multiple adjustments of the deviation compensation gain value specifically include:

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

[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 deviation compensation gain after the first adjustment is K1=1.1×K0, where K0 is the current deviation compensation gain of the system;

[0022] 3) Based on the deviation compensation gain K1 after the first adjustment, the final control output u of each hydraulic actuator is re-obtained i1 ;

[0023] 4) According to the final control output u of each hydraulic actuator that is retrieved i1 , calculate the synchronization accuracy T1 of the multi-hydraulic actuator system 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 after the second adjustment is K2=1.1×K1;

[0025] 6) Repeat the above steps. If the deviation compensation gain K after the nth adjustment is n , the calculated synchronization accuracy T of the multi-hydraulic actuator system n If the value is not lower than the preset value T, each hydraulic actuator is controlled to execute the current final control output u in , where n≥3.

[0026] Among them, if K n If the error compensation gain exceeds the preset threshold, then the error compensation gain K adjusted for the n-1th time is 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 .

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

[0028] 1. The present invention can flexibly and efficiently adjust the synchronization control accuracy of multiple hydraulic actuators by adding a synchronization deviation compensation link between the closed-loop controller output and the control element, and can be applied to the synchronization control of a large number of hydraulic actuators;

[0029] 2. The single-circuit closed-loop control and synchronous deviation compensation control of each hydraulic actuator of the present invention are designed relatively independently, and the synchronization accuracy can be adjusted through the deviation compensation gain, which can effectively improve the flexibility and control accuracy of the synchronous control of multiple hydraulic actuators. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Flow chart of a method for synchronously controlling multiple hydraulic actuators in an embodiment of the present invention;

[0031] Figure 2 It is a principle block diagram of a synchronous control method for multiple hydraulic actuators in an embodiment of the present invention;

[0032] Figure 3 It is a principle block diagram of synchronization deviation compensation calculation in an embodiment of the present invention;

[0033] Figure 4 It is a schematic diagram of control results when the characteristics of the reverse bucket actuators of four water jet propulsion devices on a ship in an embodiment of the present invention change without using the control method of the present invention;

[0034] Figure 5It is a schematic diagram of synchronization deviation when the characteristics of the reverse bucket actuators of four water jet propulsion devices on a ship in an embodiment of the present invention change without using the control method of the present invention;

[0035] Figure 6 It is a schematic diagram of control results of the control method of the present invention when the characteristics of the actuators of the reverse buckets of four water jet propulsion devices of a certain ship change in an embodiment of the present invention;

[0036] Figure 7 It is a schematic diagram of synchronization deviation of the control method of the present invention when the characteristics of the reverse bucket actuators of four water jet propulsion devices on a ship change in an embodiment of the present invention;

[0037] Figure 8 It is a schematic diagram of control results when the characteristics of the reverse bucket actuators of four water jet propulsion devices on a ship change in an embodiment of the present invention, using the control method of the present invention and increasing the deviation compensation gain;

[0038] Fig. 9 It is a schematic diagram of synchronization deviation when the characteristics of the reverse bucket actuators of four water jet propulsion devices on a ship change in an embodiment of the present invention, using the control method of the present invention and increasing the deviation compensation gain. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention 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, the various steps / components described in this application can be split into more steps / components, and two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0041] Embodiment 1: This embodiment provides a method for synchronously controlling multiple hydraulic actuators. Figures 1 to 3 As shown, it mainly includes the following steps:

[0042] S1, design of closed-loop controller for single hydraulic actuator: without considering synchronous control, design of single-loop output feedback closed-loop controller for each hydraulic actuator is performed separately;

[0043] S2, design the synchronization deviation compensation link: calculate the synchronization deviation compensation amount of each hydraulic actuator according to the output feedback parameters of each hydraulic actuator and their average values;

[0044] S3, debugging the 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, and the deviation compensation gain is kept unchanged. At the same time, each hydraulic actuator executes the final control output according to the adjusted deviation compensation gain.

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

[0046] Furthermore, each of the hydraulic actuators adopts the same closed-loop controller design.

[0047] Furthermore, in step S2, the output feedback parameter of the i-th hydraulic actuator is recorded as yi, and the average value of the output feedback parameter y m The details are as follows:

[0048]

[0049] Where n is the number of hydraulic actuators.

[0050] Furthermore, 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 synchronous deviation compensation of the i-th hydraulic actuator, and K is the deviation compensation gain.

[0053] Furthermore, the closed-loop controller output u of the i-th hydraulic actuator is 0i After limiting the effective input range of the control unit, the corresponding synchronous deviation compensation value u ci After adding and limiting according to the effective input range of the control unit again, the final control output u of the i-th hydraulic actuator is obtained. i .

[0054] Furthermore, in step S3, the multiple adjustments of the deviation compensation gain value specifically include:

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

[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 deviation compensation gain after the first adjustment is K1=1.1×K0, where K0 is the current deviation compensation gain of the system;

[0057] 3) Based on the deviation compensation gain K1 after the first adjustment, the final control output u of each hydraulic actuator is re-obtained i1 ;

[0058] 4) According to the final control output u of each hydraulic actuator that is retrieved 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, the deviation compensation gain K1 is adjusted for the second time, and the deviation compensation gain after the second adjustment is K2=1.1×K1;

[0060] 6) Repeat the above steps. If the deviation compensation gain K after the nth adjustment is n , the calculated synchronization accuracy T of the multi-hydraulic actuator system n If the value is not lower than the preset value T, each hydraulic actuator is controlled to execute the current final control output u in , where n≥3.

[0061] Among them, if K n If the error exceeds the preset deviation compensation gain threshold, then the error compensation gain K adjusted for the n-1th time is 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 .

[0062] Embodiment 2: This embodiment provides a method for synchronously controlling multiple hydraulic actuators, comprising:

[0063] Step 1: Complete the design of closed-loop controller for single hydraulic actuator;

[0064] Step 2: Design synchronization deviation compensation link;

[0065] Step 3: Debug the deviation compensation gain.

[0066] Furthermore, in step 1, the method specifically includes:

[0067] Without considering synchronous control, the closed-loop controller design of the single hydraulic actuator is completed according to the conventional single-loop output feedback control method. After debugging, it meets the closed-loop control index requirements.

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

[0069] Each hydraulic actuator uses this controller.

[0070] Furthermore, in step 2, the method specifically includes:

[0071] According to the feedback parameters y of each hydraulic actuator i , calculate the mean value y m :

[0072]

[0073] Where n is the number of actuators.

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

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

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

[0077] The output u of the closed-loop controller 0i After the effective input range of the control unit is limited, the synchronous deviation compensation amount u ci Add, and again limit the effective input range of the control unit to obtain 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, too large a K value will also reduce system stability.

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

[0082] This embodiment takes a certain ship as an example, which is equipped with four water jet propulsion devices. The adjustment of the reverse bucket angle and the rudder angle are driven by hydraulic cylinders, and the hydraulic systems of each water jet propulsion device are independent. Due to the compartment layout of the hydraulic pump station, the pipeline designs of the four hydraulic systems are quite different.

[0083] The water jet propulsion control unit is equipped with an amplifier board that drives the proportional valve, and the hydraulic cylinder speed is adjusted by the proportional valve opening. The angle closed-loop control is realized by the propulsion remote control system, which provides application conditions for synchronous control.

[0084] The four system angle closed loops are controlled by the same set of PID parameters. Differentiate the parameters of the four systems to make the system produce synchronization deviation. The angle control response of the reverse bucket is as follows: Figure 4 As shown, the dotted line in the figure is the angle instruction. Figure 5is the synchronization deviation of each pump, which is defined here as the deviation of each pump angle from the average angle of the four pumps. It can be seen that the maximum deviation is 5.3 degrees.

[0085] Therefore, the control method of the present invention is adopted, and a synchronization deviation compensation link is added between the original PID controller and the control element. The algorithm is shown in Figure 2 and Figure 3 . Figure 3 The limiting link after the central control output cannot be omitted to avoid the deviation compensation output being too small and unable to play a role when the controller is seriously saturated. The reverse angle control result at this time is shown in Figure 6 . Figure 7 is the synchronization deviation of each pump, with a maximum deviation of 2.3°.

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

[0087] It can be seen from the above technical scheme that in the multi-hydraulic actuator synchronous control method provided by the above embodiment of the present invention, each single-circuit closed-loop control design and synchronous deviation compensation control can be designed relatively independently; the synchronization accuracy can be adjusted through the deviation compensation gain; and it is not limited by the number of hydraulic actuators.

[0088] Furthermore, all parts involved in this application that are not described in detail are the same as the prior art or are implemented using the prior art.

[0089] In summary:

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

[0091] 2. The single-circuit closed-loop control and synchronous deviation compensation control of each hydraulic actuator of the present invention are designed relatively independently, and the synchronization accuracy can be adjusted through the deviation compensation gain, which can effectively improve the flexibility and control accuracy of the synchronous control of multiple hydraulic actuators.

[0092] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for synchronous control of multiple hydraulic actuators, characterized in that: The steps include: S1, design of closed-loop controller for single hydraulic actuator: without considering synchronous control, design of single-loop output feedback closed-loop controller for each hydraulic actuator is performed separately; S2, design the synchronization deviation compensation link: calculate the synchronization deviation compensation amount of each hydraulic actuator according to the output feedback parameters of each hydraulic actuator and their average values; S3, debugging the 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, and the deviation compensation gain is kept unchanged. At the same time, each hydraulic actuator executes the final control output according to the adjusted deviation compensation gain.

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

3. A method for synchronously controlling multiple hydraulic actuators according to claim 2, characterized in that: Each of the hydraulic actuators is designed with the same closed-loop controller.

4. A method for synchronously controlling multiple hydraulic actuators according to claim 1, characterized in that In step S2, the output feedback parameter of the i-th hydraulic actuator is recorded as yi, and the average value of the output feedback parameter y m The details are as follows: Where n is the number of hydraulic actuators.

5. A method for synchronously controlling multiple hydraulic actuators according to claim 4, characterized in that: The synchronous deviation compensation amount of each hydraulic actuator is calculated as follows: or ci =K(and m -and i ) In the formula, u ci is the synchronous deviation compensation of the i-th hydraulic actuator, and K is the deviation compensation gain.

6. A method for synchronously controlling multiple hydraulic actuators according to claim 5, characterized in that: The closed-loop controller output u for the i-th hydraulic actuator is 0i After limiting the effective input range of the control unit, the corresponding synchronous deviation compensation value u ci After adding and limiting according to the effective input range of the control unit again, the final control output u of the i-th hydraulic actuator is obtained. i .

7. A method for synchronously controlling multiple hydraulic actuators according to claim 6, characterized in that In step S3, the multiple adjustment of the deviation compensation gain value specifically includes: 1) According to 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, and 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, the final control output u of each hydraulic actuator is re-obtained i1 ; 4) According to the final control output u of each hydraulic actuator that is retrieved 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, and the deviation compensation gain after the second adjustment is K2=1.1×K1; 6) Repeat the above steps. If the deviation compensation gain K after the nth adjustment is n , the calculated synchronization accuracy T of the multi-hydraulic actuator system n If the value is not lower than the preset value T, each hydraulic actuator is controlled to execute the current final control output u in , where n≥3.

8. A method for synchronously controlling multiple hydraulic actuators according to claim 7, characterized in that: If K n If the error exceeds the preset deviation compensation gain threshold, then the error compensation gain K adjusted for the n-1th time is 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 .

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