Multi-cylinder synchronous control method and system based on PI algorithm

Abstract

The present invention provides a multi-cylinder synchronous control method and system based on PI algorithm, and relates to the field of hydraulic motion control synchronization technology. The present invention adopts a PI control strategy with the advantages of fast response, small overshoot and small steady-state error in the control algorithm, firstly obtains the basic fixed value of the analog signal used to control the movement of the cylinder; and obtains the displacement difference of two adjacent cylinders in the kth sampling cycle and the accumulated value of the displacement difference within the k sampling cycles; then obtains the analog signal value corresponding to each cylinder in real time based on the basic fixed value, proportional coefficient and integral coefficient; finally, performs high-precision synchronous control of the multi-cylinder mechanism based on the analog signal value of each cylinder.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic motion control synchronization, and in particular to a multi-cylinder synchronization control method and system based on a PI algorithm. Background Art

[0002] Multi-cylinder synchronous control technology is applied to the flipping, folding and lateral extension and retracting mechanism of the radar antenna, which can meet the needs of a large expansion-contraction ratio of the radar array, solve the problems of rapid installation and withdrawal and high-mobility transportation of low-frequency and large-aperture radar antennas, meet the needs of mobile deployment and improve battlefield survivability.

[0003] The traditional multi-cylinder synchronization adopts the "slave follows the active" PI control strategy, which is often used for synchronizing two cylinders, one is the active cylinder with a fixed speed, and the other follows the active cylinder according to the displacement difference.

[0004] The above method has the problem of low synchronization accuracy in actual use. Summary of the invention

[0005] 1. Technical issues to be solved

[0006] In view of the deficiencies in the prior art, the present invention provides a multi-cylinder synchronization control method and system based on a PI algorithm, which solves the problem of poor synchronization accuracy of the existing multi-cylinder synchronization control method.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] In a first aspect, a multi-cylinder synchronous control method based on a PI algorithm is provided, the method comprising:

[0010] Get the basic constant value of the analog signal used to control the movement of the cylinder;

[0011] Obtain the displacement difference between two adjacent oil cylinders in the kth sampling period and the accumulated value of the displacement difference within k sampling periods;

[0012] Obtain the proportional coefficient and integral coefficient of each oil cylinder, and obtain the analog signal value corresponding to each oil cylinder in real time based on the basic set value, proportional coefficient and integral coefficient;

[0013] Synchronous control is performed based on the analog signal value of each cylinder.

[0014] Furthermore, the real-time acquisition of the analog signal value corresponding to each oil cylinder based on the basic fixed value, the proportional coefficient and the integral coefficient includes:

[0015] For the 1st to N-1st cylinders, based on the proportional coefficient, integral coefficient, displacement difference between the nth and n-1th cylinders in the kth sampling period, and the accumulated displacement difference within the kth sampling period, the analog signal value U of the n-1th cylinder in the kth sampling period is obtained. (n-1)(k) ; where n=2,...,N.

[0016] Furthermore, the analog signal value U of the n-1th cylinder in the kth sampling period (n-1)(k) The calculation formula is:

[0017]

[0018] ΔS (n)(n-1)(k) =S (n)(k) -S (n-1)(k)

[0019]

[0020] in,

[0021] K (P)(n-1) Indicates the proportional coefficient of the n-1th cylinder;

[0022] K (I)(n-1) Indicates the integral coefficient of the n-1th cylinder;

[0023] S (n)(k) Represents the displacement signal of the nth cylinder in the kth sampling period;

[0024] ΔS (n)(n-1)(k) It represents the displacement difference between the nth and n-1th cylinders in the kth sampling period;

[0025] It represents the accumulated value of the displacement difference between the nth and n-1th cylinders in k sampling periods;

[0026] U0 represents the basic constant of the analog signal.

[0027] Furthermore, the real-time acquisition of the analog signal value corresponding to each oil cylinder based on the basic fixed value, the proportional coefficient and the integral coefficient also includes:

[0028] For the Nth cylinder, based on the proportional coefficient, integral coefficient, displacement difference between the Nth and 1st cylinders in the kth sampling period, and the accumulated displacement difference within k sampling periods, the analog signal value U of the Nth cylinder in the kth sampling period is obtained. (N)(k) .

[0029] Furthermore, the analog signal value U of the Nth cylinder in the kth sampling period (N)(k) The calculation formula is:

[0030]

[0031] in,

[0032] K (P)(N) Indicates the proportional coefficient of the Nth cylinder;

[0033] K (I)(N) Indicates the integral coefficient of the Nth cylinder

[0034] ΔS (1)(N)(k) It represents the displacement difference between the 1st cylinder and the Nth cylinder in the kth sampling period;

[0035] It represents the accumulated value of the displacement difference between the 1st cylinder and the Nth cylinder in k sampling periods.

[0036] In a second aspect, a multi-cylinder synchronous control system based on a PI algorithm is provided, the system comprising:

[0037] A controller, used for generating analog signal quantities corresponding to each cylinder based on the displacement signals of each cylinder;

[0038] A number of amplifiers matching the number of oil cylinders are used to convert the analog signal output by the controller into the current signal required to drive the proportional reversing valve;

[0039] A number of proportional reversing valves matching the number of cylinders are used to control the movement of the cylinders according to analog signals;

[0040] A number of displacement sensors matching the number of oil cylinders are used to obtain displacement signals of each oil cylinder;

[0041] The controller generates analog signal quantities corresponding to each cylinder based on the displacement signals of each cylinder, including:

[0042] Get the basic constant value of the analog signal used to control the movement of the cylinder;

[0043] Obtain the displacement difference between two adjacent oil cylinders in the kth sampling period and the accumulated value of the displacement difference within k sampling periods;

[0044] The proportional coefficient and integral coefficient of each cylinder are obtained, and the analog signal value corresponding to each cylinder is obtained in real time based on the basic set value, the proportional coefficient and the integral coefficient.

[0045] Furthermore, the real-time acquisition of the analog signal value corresponding to each oil cylinder based on the basic fixed value, the proportional coefficient and the integral coefficient includes:

[0046] For the 1st to N-1st cylinders, based on the proportional coefficient, integral coefficient, displacement difference between the nth and n-1th cylinders in the kth sampling period, and the accumulated displacement difference within the kth sampling period, the analog signal value U of the n-1th cylinder in the kth sampling period is obtained. (n-1)(k) ; where n=2,...,N.

[0047] Furthermore, the analog signal value U of the n-1th cylinder in the kth sampling period (n-1)(k) The calculation formula is:

[0048]

[0049] ΔS (n)(n-1)(k) =S (n)(k) -S (n-1)(k)

[0050]

[0051] in,

[0052] K (P)(n-1) Indicates the proportional coefficient of the n-1th cylinder;

[0053] K (I)(n-1) Indicates the integral coefficient of the n-1th cylinder;

[0054] S (n)(k) Represents the displacement signal of the nth cylinder in the kth sampling period;

[0055] ΔS (n)(n-1)(k) It represents the displacement difference between the nth and n-1th cylinders in the kth sampling period;

[0056] It represents the accumulated value of the displacement difference between the nth and n-1th cylinders in k sampling periods;

[0057] U0 represents the basic constant of the analog signal.

[0058] Furthermore, the real-time acquisition of the analog signal value corresponding to each oil cylinder based on the basic fixed value, the proportional coefficient and the integral coefficient also includes:

[0059] For the Nth cylinder, based on the proportional coefficient, integral coefficient, displacement difference between the Nth and 1st cylinders in the kth sampling period, and the accumulated displacement difference within k sampling periods, the analog signal value U of the Nth cylinder in the kth sampling period is obtained. (N)(k) .

[0060] Furthermore, the analog signal value U of the Nth cylinder in the kth sampling period (N)(k) The calculation formula is:

[0061]

[0062] in,

[0063] K (P)(N) Indicates the proportional coefficient of the Nth cylinder;

[0064] K (I)(N) Indicates the integral coefficient of the Nth cylinder

[0065] ΔS (1)(N)(k) It represents the displacement difference between the 1st cylinder and the Nth cylinder in the kth sampling period;

[0066] It represents the accumulated value of the displacement difference between the 1st cylinder and the Nth cylinder in k sampling periods.

[0067] (III) Beneficial effects

[0068] The present invention provides a multi-cylinder synchronous control method and system based on PI algorithm. Compared with the prior art, it has the following beneficial effects:

[0069] The present invention adopts a PI control strategy with the advantages of fast response, small overshoot and small steady-state error in the control algorithm. First, the basic constant of the analog signal used to control the movement of the cylinder is obtained; and the displacement difference of two adjacent cylinders in the kth sampling period and the accumulated value of the displacement difference within k sampling periods are obtained; then, based on the basic constant, the proportional coefficient and the integral coefficient, the analog signal value corresponding to each cylinder is obtained in real time; finally, based on the analog signal value of each cylinder, high-precision synchronous control of the multi-cylinder mechanism is performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0071] Figure 1 is a flow chart of the present invention;

[0072] Figure 2 It is a schematic structural diagram of the antenna array skeleton of Example 1 of the present invention;

[0073] Figure 3 It is a system principle diagram of the present invention. DETAILED DESCRIPTION

[0074] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0075] The embodiment of the present application solves the problem of poor synchronization accuracy of the existing multi-cylinder synchronization control method by providing a multi-cylinder synchronization control method and system based on the PI algorithm.

[0076] The technical solution in the embodiment of the present application is to solve the above technical problems, and the overall idea is as follows:

[0077] The inventors have found that the disadvantage of the existing "slave follows the active" PI control strategy is that the other cylinder always lags behind the active cylinder, and the overall speed depends on the active cylinder. If the master cylinder is slowed down by external factors and cannot self-regulate, the overall speed will decrease, and accurate synchronization in motion cannot be achieved.

[0078] In view of the defects of the prior art and the needs of large-caliber radar antennas, the present invention provides a multi-cylinder synchronous control method based on a PI algorithm. The PI control strategy with the advantages of fast response, small overshoot and small steady-state error is adopted in the control algorithm. First, a basic constant of an analog signal for controlling the movement of the cylinder is obtained; and the displacement difference between the nth and n-1th cylinders in the kth sampling period and the accumulated value of the displacement difference within k sampling periods are obtained; then, the analog signal value corresponding to each cylinder is obtained in real time based on the basic constant, proportional coefficient and integral coefficient; finally, high-precision synchronous control of a multi-cylinder mechanism is performed based on the analog signal value of each cylinder.

[0079] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0080] Embodiment 1:

[0081] like Figure 1 As shown, the present invention provides a multi-cylinder synchronous control method based on PI algorithm, the method comprising:

[0082] Get the basic constant value of the analog signal used to control the movement of the cylinder;

[0083] Obtain the displacement difference between two adjacent oil cylinders in the kth sampling period and the accumulated value of the displacement difference within k sampling periods;

[0084] Obtain the proportional coefficient and integral coefficient of each oil cylinder, and obtain the analog signal value corresponding to each oil cylinder in real time based on the basic set value, proportional coefficient and integral coefficient;

[0085] Synchronous control is performed based on the analog signal value of each cylinder.

[0086] The beneficial effects of this embodiment are:

[0087] The present invention adopts a PI control strategy with the advantages of fast response, small overshoot and small steady-state error in the control algorithm. First, the basic constant of the analog signal used to control the movement of the cylinder is obtained; and the displacement difference of two adjacent cylinders in the kth sampling period and the accumulated value of the displacement difference within k sampling periods are obtained; based on the basic constant, the proportional coefficient and the integral coefficient, the analog signal value corresponding to each cylinder is obtained in real time; based on the analog signal value of each cylinder, high-precision synchronous control of the multi-cylinder mechanism is performed.

[0088] The following takes the large array antenna horizontal expansion synchronization control as an example to describe the implementation process of the embodiment of the present invention in detail:

[0089] The antenna array frame is composed of the left block horizontal expansion mechanism, the right block horizontal expansion mechanism and the middle block frame, such as Figure 2 As shown. The working dimensions of the radar antenna are: 11900mm (length) x 8150mm (width), and the antenna weighs 16t. A single edge block skeleton consists of 11 column skeletons, an automatically foldable reflective net, a positioning pull rod, and three sets of drive mechanisms. Each set of horizontal drive mechanisms consists of three arms, with a total of N=6 cylinders, which can be numbered in sequence according to a specified direction. During the deployment process, the hydraulic oil enters the cylinder cavity from the oil inlet at the piston rod end of the cylinder. Fixed magnetostrictive displacement sensors are installed at both ends of the cylinder to provide real-time feedback on the displacement of each cylinder. During the deployment process, the edge block skeleton must ensure the precise dynamic synchronization of the six horizontal cylinders on both sides, and the control accuracy must be within 3mm to ensure that the edge block column skeleton avoids damage to the internal electronic devices due to deformation.

[0090] like Figure 3 As shown, the control system also includes: a controller, an amplifier, and a proportional reversing valve. The controller is used to calculate the cylinder control signal (analog signal) according to the displacement of each cylinder, and then amplify the signal through the amplifier, and then control the proportional reversing valve to control the movement of each cylinder.

[0091] In view of the large distribution span of the antenna lateral drive mechanism, in order to improve control accuracy and reduce the influence of signal attenuation loss, the amplifier, reversing proportional valve and magnetostrictive displacement sensor selected in this embodiment all adopt current signal control.

[0092] Therefore, in order to realize the synchronous control of the oil cylinder of this system, the following steps are adopted:

[0093] S1. Obtain the basic constant U0 of the analog signal output by the controller for controlling the movement of the cylinder.

[0094] In specific implementation, based on the action time requirements of the multi-cylinder mechanism, the minimum opening value of the proportional reversing valve is obtained;

[0095] Based on the minimum opening value of the proportional reversing valve, the corresponding amplifier output current value and the basic set value U0 of the controller's output analog signal are derived.

[0096] Any mechanism movement has timeliness requirements. Taking radar mechanism movement as an example, a certain action time is required to be within 3 minutes. The movement speed requirement can be deduced according to the movement time and stroke, and then the corresponding analog signal value range can be obtained by calculation or actual test of single-cylinder movement.

[0097] If the mechanism movement time indicator is 3 minutes, the proportional reversing valve opening is 60% (for example, its working current range is 200ma-1000ma, and the corresponding working current for 3 minutes is 600ma), then it means that the working current of the proportional reversing valve cannot be less than 600ma, and the corresponding is the minimum opening of the proportional reversing valve. (The shorter the movement time, the larger the required proportional reversing valve opening, and the larger its working current.)

[0098] Knowing the minimum value corresponding to the opening degree of the proportional reversing valve, it can be known that the working current of the proportional reversing valve at this time, that is, the output current of the amplifier, can be inferred from the input of the amplifier, that is, the output analog signal value of the controller.

[0099] In response to the problem of overall speed reduction in the prior art, when determining the basic set value U0 of the analog signal, it can be set to a value of the analog signal that is greater than the motion time index. For example, the analog signal corresponding to the action time index may be 600mA, and the maximum working current (maximum opening) of the proportional valve corresponds to 1000mA. The corresponding signal value of about 800mA can be taken as U0. This ensures that the motion time is within the time index and leaves room for speed regulation, so that the basic set value can ensure the timeliness of the entire motion mechanism and avoid the problem of overall speed reduction in the prior art.

[0100] S2. When the multi-cylinder mechanism is to perform an action, the displacement signal S fed back by the displacement sensor of each cylinder is obtained based on the sampling period. (n)(k) , and calculate the displacement difference ΔS between two adjacent cylinders in the kth sampling period (n)(n-1)(k) And the accumulated displacement difference within k sampling periods

[0101] In specific implementation, when the multi-cylinder mechanism is to perform an action, the controller records the displacement signal fed back by each cylinder displacement sensor through the displacement sensor according to the sampling period (for example, 5ms), which is recorded as:

[0102] S (1)(k) , S (2)(k) , S (3)(k) , S (4)(k) , S (5)(k) , S (6)(k)

[0103] in,

[0104] S (1)(k) It represents the displacement value recorded by the first cylinder in the kth sampling period;

[0105] S (2)(k) represents the displacement value recorded by the second cylinder in the kth sampling period;

[0106] S (3)(k) represents the displacement value recorded by the third cylinder in the kth sampling period;

[0107] S (4)(k) represents the displacement value recorded by the 4th cylinder in the kth sampling period;

[0108] S (5)(k) represents the displacement value recorded by the 5th cylinder in the kth sampling period;

[0109] S (6)(k) Represents the displacement value recorded by the 6th cylinder in the kth sampling period.

[0110] Based on the above displacement signal, the displacement difference between two adjacent cylinders in the kth sampling period can be calculated, which is recorded as: ΔS (n)(n-1)(k) =S (n)(k) -S (n-1)(k) .

[0111] For example, ΔS (2)(1)(k) Represents the displacement difference between the second cylinder and the first cylinder in the kth sampling period.

[0112] Similarly, the accumulated value of the corresponding displacement difference within k periods can be further calculated, which is recorded as:

[0113]

[0114] S3. Obtain the proportional coefficient K of each cylinder (P)(n) and the integral coefficient K (I)(n) , and based on the basic set value, proportional coefficient and integral coefficient, the analog signal value corresponding to each cylinder is obtained in real time.

[0115] In specific implementation, the proportional coefficient K can be selected using the PI regulator of Matlab (P)(n) and the integral coefficient K (I)(n) :First, adjust the proportional coefficient K (P) , first set the integral coefficient to 0, perform pure proportional adjustment, start from 0 and gradually increase until the system oscillates, then gradually decrease until the oscillation disappears, record K (P) Select an appropriate value from the range of K. (P) Later, set a larger integral time constant K (I) , then gradually decrease until oscillation occurs, and then conversely, gradually increase until the system oscillation disappears, and record the K at this time (I) In actual use, it can be revised again according to the actual use effect. Because the distance between two adjacent cylinders and their loads are consistent according to the structural design characteristics, the proportional coefficient and integral coefficient of each cylinder can use the same value.

[0116] like Figure 3 As shown in the figure, for the 1st to N-1th cylinders, the PI control algorithm is used to achieve the synchronization of the n-1th cylinder and its adjacent nth cylinder. The controller outputs the analog signal value U corresponding to the cylinder n-1 in the kth sampling period. (n-1)(k) , and the formula is as follows:

[0117]

[0118] For the Nth cylinder, in order to prevent other factors from slowing down its speed and affecting the timeliness of the entire multi-cylinder mechanism, the PI control algorithm is used to make the nth cylinder synchronously track the first cylinder. The PI synchronization algorithm realizes closed-loop tracking. The programmable controller outputs the analog signal value U of the Nth cylinder. (N)(k) , and the formula is as follows:

[0119]

[0120] Usually, the cylinders of a multi-cylinder mechanism have the same spacing and approximately the same load, so an adjacent cylinder refers to a cylinder that is closest to the cylinder in one direction in the structural layout of the multi-cylinder mechanism.

[0121] S4, based on the analog signal value U of each cylinder (n)(k) Perform synchronous control.

[0122] During specific implementation, the oil flow rate can be precisely controlled by controlling the opening of the proportional reversing valve.

[0123] A large amount of practice has proved that the horizontal expansion synchronization control system can achieve the synchronization of the extension and retraction actions of the six groups of cylinders, and the dynamic displacement difference is less than 2mm, which meets the precision requirements and effectively protects the edge block column skeleton, while ensuring the array accuracy. It solves the problem of rapid installation and withdrawal and high-mobility transportation of low-frequency and large-aperture radar antennas, and solves the bottleneck problem for the smooth development of a certain radar project.

[0124] In addition, in case of abnormal factors such as structural obstruction and blockage of hydraulic components in the multi-cylinder system, the synchronization effect cannot be corrected by speed regulation alone. Therefore, the embodiment of the present invention can further determine an out-of-tolerance threshold value according to the structural characteristics. If the deviation exceeds a certain amplitude, the control system will automatically stop the action and alarm. For example, the out-of-tolerance threshold value is set to 10mm, and the normal adjustment accuracy is within 2mm. In specific implementation, the alarm threshold value setting and arrangement of cylinder n tracking cylinder 1 are related. If it is arranged in a ring, it is the same as other alarm thresholds. If it is arranged in a straight line, it is n / 2 times the other alarm valve values.

[0125] Obviously, the control algorithm of the embodiment of the present invention is not a simple one-way chasing of the active cylinder, but a cyclic chasing of all cylinders. The speed of each cylinder can be adjusted, and there is no active cylinder that cannot be adjusted. Moreover, the existing controller can achieve an adjustment cycle within 10ms, and the amplitude of the speed adjustment is within 200mA. In this way, the time index will not be affected by the speed adjustment, ensuring that the system completes the action within the time index.

[0126] Example 2

[0127] The present invention also provides a multi-cylinder synchronous control system based on PI algorithm, the system comprising:

[0128] A controller, used for generating analog signal quantities corresponding to each cylinder based on the displacement signals of each cylinder;

[0129] There are several amplifiers that match the number of cylinders. Since the signal current output by the controller is weak and not enough to drive the proportional reversing valve, the amplifier is needed as a signal matcher to receive the analog signal of weak current and output the current required by the corresponding proportional solenoid.

[0130] In addition, the amplifier can also process the signal by adjusting dead zone, gain, ramp time, and dither.

[0131] A number of proportional reversing valves matching the number of cylinders are used to control the movement of the cylinders according to analog signals;

[0132] A number of displacement sensors matching the number of oil cylinders are used to obtain displacement signals of each oil cylinder;

[0133] The controller generates analog signal quantities corresponding to each cylinder based on the displacement signals of each cylinder, including:

[0134] Get the basic constant value of the analog signal used to control the movement of the cylinder;

[0135] Obtain the displacement difference between two adjacent oil cylinders in the kth sampling period and the accumulated value of the displacement difference within k sampling periods;

[0136] The proportional coefficient and integral coefficient of each cylinder are obtained, and the analog signal value corresponding to each cylinder is obtained in real time based on the basic set value, the proportional coefficient and the integral coefficient.

[0137] It can be understood that the multi-cylinder synchronous control system based on PI algorithm provided in an embodiment of the present invention corresponds to the above-mentioned multi-cylinder synchronous control method based on PI algorithm. The explanations, examples, beneficial effects and other parts of the relevant contents can refer to the corresponding contents in the multi-cylinder synchronous control method based on PI algorithm, and will not be repeated here.

[0138] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0139] ① The present invention adopts a PI control strategy with the advantages of fast response, small overshoot and small steady-state error in the control algorithm. First, the basic constant of the analog signal used to control the movement of the cylinder is obtained; and the displacement difference of two adjacent cylinders in the kth sampling period and the accumulated value of the displacement difference within k sampling periods are obtained; based on the basic constant, proportional coefficient and integral coefficient, the analog signal value corresponding to each cylinder is obtained in real time; based on the analog signal value of each cylinder, high-precision synchronous control of the multi-cylinder mechanism is performed.

[0140] ② By setting the basic constant value U0 of the output analog signal of the controller, the motion time is ensured to be within the time index, and space is left for speed regulation, so that the basic constant value can ensure the timeliness of the entire motion mechanism, avoiding the problem of overall speed reduction in the prior art. At the same time, combined with the control algorithm of the present invention, there is no active cylinder, avoiding the problem of overall speed reduction in the prior art.

[0141] It should be noted that, through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which can be stored in a storage medium, such as ROM / RAM, a disk, an optical disk, etc., including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiment. In this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements inherent to such process, method, article or device. Without more constraints, an element defined by the phrase "comprising a..." does not exclude the existence of other identical elements in the process, method, article or apparatus comprising the element.

[0142] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-cylinder synchronous control method based on PI algorithm, characterized in that: The method includes: Get the basic constant value of the analog signal used to control the movement of the cylinder; Obtain the displacement difference between two adjacent oil cylinders in the kth sampling period and the accumulated value of the displacement difference within k sampling periods; Obtain the proportional coefficient and integral coefficient of each oil cylinder, and obtain the analog signal value corresponding to each oil cylinder in real time based on the basic set value, proportional coefficient and integral coefficient; Synchronous control based on the analog signal value of each cylinder; The method of obtaining the analog signal value corresponding to each oil cylinder in real time based on the basic fixed value, the proportional coefficient and the integral coefficient includes: For the 1st to N-1st cylinders, based on the proportional coefficient, integral coefficient, displacement difference between the nth and n-1th cylinders in the kth sampling period, and the accumulated displacement difference within the kth sampling period, the analog signal value U of the n-1th cylinder in the kth sampling period is obtained. (n-1)(k) ; Where n = 2, ..., N; The analog signal value U of the n-1th cylinder in the kth sampling period (n-1)(k) The calculation formula is: ΔS (n)(n-1)(k) =S (n)(k) -S (n-1)(k) in, K (P)(n-1) Indicates the proportional coefficient of the n-1th cylinder; K (I)(n-1) Indicates the integral coefficient of the n-1th cylinder; S (n)(k) Represents the displacement signal of the nth cylinder in the kth sampling period; ΔS (n)(n-1)(k) It represents the displacement difference between the nth and n-1th cylinders in the kth sampling period; It represents the accumulated value of the displacement difference between the nth and n-1th cylinders in k sampling periods; U0 represents the basic constant value of the analog signal; The method of acquiring the analog signal value corresponding to each oil cylinder in real time based on the basic fixed value, the proportional coefficient and the integral coefficient also includes: For the Nth cylinder, based on the proportional coefficient, integral coefficient, displacement difference between the Nth and 1st cylinders in the kth sampling period, and the accumulated displacement difference within k sampling periods, the analog signal value U of the Nth cylinder in the kth sampling period is obtained. (N)(k) ; The analog signal value U of the Nth cylinder in the kth sampling period (N)(k) The calculation formula is: in, K (P)(N) Indicates the proportional coefficient of the Nth cylinder; K (I)(N) Indicates the integral coefficient of the Nth cylinder ΔS (1)(N)(k) It represents the displacement difference between the 1st cylinder and the Nth cylinder in the kth sampling period; It represents the accumulated value of the displacement difference between the 1st cylinder and the Nth cylinder in k sampling periods.

2. A multi-cylinder synchronous control system based on PI algorithm, characterized in that: The system comprises: A controller, used for generating analog signal quantities corresponding to each cylinder based on the displacement signals of each cylinder; A number of amplifiers matching the number of oil cylinders are used to convert the analog signal output by the controller into the current signal required to drive the proportional reversing valve; A number of proportional reversing valves matching the number of cylinders are used to control the movement of the cylinders according to analog signals; A number of displacement sensors matching the number of oil cylinders are used to obtain displacement signals of each oil cylinder; The controller generates analog signal quantities corresponding to each cylinder based on the displacement signals of each cylinder, including: Get the basic constant value of the analog signal used to control the movement of the cylinder; Obtain the displacement difference between two adjacent oil cylinders in the kth sampling period and the accumulated value of the displacement difference within k sampling periods; Obtain the proportional coefficient and integral coefficient of each oil cylinder, and obtain the analog signal value corresponding to each oil cylinder in real time based on the basic set value, proportional coefficient and integral coefficient; The method of obtaining the analog signal value corresponding to each oil cylinder in real time based on the basic fixed value, the proportional coefficient and the integral coefficient includes: For the 1st to N-1st cylinders, based on the proportional coefficient, integral coefficient, displacement difference between the nth and n-1th cylinders in the kth sampling period, and the accumulated displacement difference within the kth sampling period, the analog signal value U of the n-1th cylinder in the kth sampling period is obtained. (n-1)(k) ; Where n = 2, ..., N; The analog signal value U of the n-1th cylinder in the kth sampling period (n-1)(k) The calculation formula is: ΔS (n)(n-1)(k) =S (n)(k) -S (n-1)(k) in, K (P)(n-1) Indicates the proportional coefficient of the n-1th cylinder; K (I)(n-1) Indicates the integral coefficient of the n-1th cylinder; S (n)(k) Represents the displacement signal of the nth cylinder in the kth sampling period; ΔS (n)(n-1)(k) It represents the displacement difference between the nth and n-1th cylinders in the kth sampling period; It represents the accumulated value of the displacement difference between the nth and n-1th cylinders in k sampling periods; U0 represents the basic constant value of the analog signal; The method of acquiring the analog signal value corresponding to each oil cylinder in real time based on the basic fixed value, the proportional coefficient and the integral coefficient also includes: For the Nth cylinder, based on the proportional coefficient, integral coefficient, displacement difference between the Nth and 1st cylinders in the kth sampling period, and the accumulated displacement difference within k sampling periods, the analog signal value U of the Nth cylinder in the kth sampling period is obtained. (N)(k) ; The analog signal value U of the Nth cylinder in the kth sampling period (N)(k) The calculation formula is: in, K (P)(N) Indicates the proportional coefficient of the Nth cylinder; K (I)(N) Indicates the integral coefficient of the Nth cylinder ΔS (1)(N)(k) It represents the displacement difference between the 1st cylinder and the Nth cylinder in the kth sampling period; It represents the accumulated value of the displacement difference between the 1st cylinder and the Nth cylinder in k sampling periods.

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