A control method for synchronous operation of a double pusher chain device lifting platform

Abstract

A kind of control method of double push chain device lifting platform synchronous operation, belong to push chain lifting platform technical field, including the following steps: (1) the position of the push chain head of two push chain devices is detected;(2) the speed of two push chains is calculated;(3) the height difference of the push chain head of two push chains is calculated;(4) the push force of the push chain head of two push chains is read;(5) the push force difference of the push chain head of two push chains is calculated;(6) according to fuzzy rule base, judge the unbalance load condition, and calculate compensation frequency and compensation time.The present application solves the synchronization problem and unbalance load problem in the operation of two push chain device lifting platforms, improves the load capacity of the lifting platform, improves the stability of the lifting platform, and prolongs the service life of the lifting platform.

Description

Technical Field

[0001] This invention belongs to the technical field of push chain lifting platforms, specifically relating to a control method for the synchronous operation of a dual push chain lifting platform. Background Technology

[0002] The push chain device can withstand both tensile and compressive forces, possesses strong rigidity, maintains a good shape during vertical pushing, has a stable structure, and a large load-bearing capacity. It is widely used in the logistics and automation industries, accurately pushing goods to designated locations at high speeds with precise position control, greatly improving production efficiency and capacity.

[0003] However, in heavy-duty applications, the thrust of a single push chain device is limited, necessitating the simultaneous use of two push chain devices to lift the same load, as illustrated in patent document CN120463123A, which discloses a push chain-type synchronous lifting platform and its control method. As with the mechanical structure provided in this patent document, the operation of a lifting platform with two push chain devices presents two challenges: firstly, achieving synchronization between the two push chain devices is difficult; secondly, the lifting platform is prone to uneven loading, resulting in significant load differences between each push chain device and causing unstable operation. To ensure load balance between the two push chain devices, their speed and position must be synchronized during operation. Summary of the Invention

[0004] This invention discloses a control method for the synchronous operation of a dual-push-chain lifting platform. The aim is to solve the synchronization and off-center loading problems of the two push-chain lifting platforms, increase the load capacity, improve the stability, and extend the service life of the lifting platform. The specific structure of the dual-push-chain lifting platform involved in this invention can be found in patent document CN120463123A.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A control method for synchronous operation of a lifting platform with a dual-push chain device includes the following steps:

[0007] (1) Detect the position of the push link heads of the two push chain devices;

[0008] (2) Calculate the velocities of the two push chains;

[0009] (3) Calculate the position difference between the headers of the two push links;

[0010] (4) Read the push force of the two push link headers;

[0011] (5) Calculate the thrust difference between the two push links;

[0012] (6) Determine the off-load status based on the fuzzy rule base and calculate the compensation frequency and compensation time.

[0013] Preferably, in step (1), each of the two push chain devices is equipped with one three-phase motor as a drive motor, namely three-phase motor M1 and three-phase motor M2, and each three-phase motor is equipped with an independent frequency converter for drive; three-phase motor M1 is the main motor, and three-phase motor M2 is the slave motor, and the speed, position, and thrust of the main motor are set to the target values ​​of the slave motor; the position of the push chain device joint is detected by the encoder of the three-phase motor. and .

[0014] Preferably, in step (2), the position of the push link header is collected at time intervals T. and , and Calculate the speed of the push chain device joint. and .

[0015] Preferably, in step (3), the difference in the joint position between the two push chain devices is... .

[0016] Preferably, in step (4), the push chain connectors output by the two push chain devices are connected to the bottom of the platform via tension and compression sensors, and the two tension and compression sensors detect the thrust of the push chain device connectors. and .

[0017] Preferably, in step (5), the thrust difference between the two push chains is... .

[0018] Preferably, in step (6), based on the fuzzy control algorithm, the position, speed and thrust of the two push link heads are dynamically collected, and the compensation frequency and compensation time of the motor M2 are inferred and calculated according to the fuzzy rule base based on two-dimensional variables.

[0019] Preferably, in step (6), in order to achieve synchronous operation of the two push chain devices and eliminate the positional deviation of the two push chain devices, a correction frequency rule library and a compensation time rule library are established respectively based on the operating experience of the push chain devices. Through the correction frequency rule library, the compensation frequency of the slave motor M2 is inferred to be equal to the operating frequency of the master motor M1 plus the correction frequency. Through the compensation time rule library, the compensation time of the slave motor M2 is inferred to be the time during which the slave motor M2 runs at the compensation frequency.

[0020] Preferably, in step (6), an off-center load inference rule base is established based on the position difference x and the thrust difference f. When the off-center load parameters of the lifting platform are... When the lifting platform is not eccentrically loaded, it is determined that the lifting platform is not eccentrically loaded; when the lifting platform's eccentricity parameter... When the lifting platform is found to be unbalanced, it is first automatically eliminated by adjusting the compensation frequency and compensation time. If the unbalanced load cannot be eliminated, the lifting platform will alarm and stop. Here, P0 is the unbalanced load judgment benchmark calculated based on experience.

[0021] The beneficial effects of the control method for synchronous operation of a dual-push chain device lifting platform of the present invention are as follows:

[0022] (1) The lifting platform of this push chain device can lift heavy loads. The platform is more stable during the lifting process and has a longer service life. It realizes synchronous control and off-center load detection of the lifting platform.

[0023] (2) The lifting platform of this push chain device can realize reciprocating lifting under heavy load and extra heavy load.

[0024] (3) The lifting platform of this push chain device realizes synchronous control of the frequency converter through the fuzzy rule base, which greatly reduces the control cost and realizes synchronous control of the frequency converter.

[0025] (4) The lifting platform of this push chain device has strong robustness and can achieve good synchronous control under different working conditions.

[0026] (5) The lifting platform of this push chain device uses tension and pressure sensors to read the thrust of the push chain device and realize the off-center load alarm detection of the lifting platform.

[0027] (6) By optimizing the operation of the two push chain devices, the service life of the lifting platform was extended.

[0028] (7) The lifting platform of this push chain device has high real-time responsiveness and can quickly eliminate the position deviation of the lifting platform. Attached Figure Description

[0029] Figure 1 : Flowchart of the method of the present invention. Detailed Implementation

[0030] The following description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0031] The following embodiments can be understood as illustrating a part of the structure or method of the present invention individually, or as combining the embodiments to explain the broader structure or method of the present invention.

[0032] Example 1:

[0033] A control method for synchronous operation of a dual-push chain lifting platform, such as... Figure 1 As shown, it includes the following steps:

[0034] (1) Detect the position of the push link heads of the two push chain devices;

[0035] (2) Calculate the velocities of the two push chains;

[0036] (3) Calculate the position difference between the headers of the two push links;

[0037] (4) Read the push force of the two push link headers;

[0038] (5) Calculate the thrust difference between the two push links;

[0039] (6) Determine the off-load status based on the fuzzy rule base and calculate the compensation frequency and compensation time.

[0040] Example 2:

[0041] Based on Embodiment 1, in step (1), each of the two push chain devices is equipped with one three-phase motor as a drive motor, namely three-phase motor M1 and three-phase motor M2, and each three-phase motor is equipped with an independent frequency converter drive; three-phase motor M1 is the main motor, and three-phase motor M2 is the slave motor. The speed, position, and thrust of the main motor are the target values ​​of the slave motor (the lifting platform has two motors. Ideally, the speed, position, and thrust of the main motor and the slave motor should be the same, so the speed, position, and thrust of the slave motor should be consistent with the parameters of the main motor); the position of the push chain device is detected by the encoder of the three-phase motor. and Based on the known design conditions of the lifting platform, including the rated speed N, rated frequency F, reduction ratio Ratio of the three-phase motor, sprocket circumference C of the push chain device, and the set operating speed Spd of the lifting platform, the conversion factor between operating speed and frequency is calculated. The operating frequency of the main motor M1 .

[0042] Example 3:

[0043] Based on Example 2, in step (2), the position of the push link header is collected at time intervals T. and , and Calculate the speed of the push chain device joint. and .

[0044] Example 4:

[0045] Based on Example 3, in step (3), the difference in the joint positions of the two push chain devices .

[0046] Example 5:

[0047] Based on Example 4, in step (4), the push joint heads of the two push chain devices are connected to the bottom of the platform via tension and compression sensors. The two tension and compression sensors detect the thrust of the two push chain device joints respectively. and .

[0048] Example 6:

[0049] Based on Example 5, in step (5), the thrust difference between the two push chains .

[0050] Example 7:

[0051] Based on Example 3, Real-time Example 4, and Real-time Example 6, and referring to the operating experience of the push chain device, the position difference x is divided into very small, small, medium, large, and very large according to Table 1; the speed V1 is divided into very slow, slow, medium, fast, and very fast according to Table 2; and the thrust difference f is divided into very small, small, medium, large, and very large according to Table 3.

[0052] Table 1. Judgment of position difference x

[0053]

[0054] Table 2 Speed ​​V1 Judgment

[0055]

[0056] Table 3. Thrust Difference f Judgment

[0057]

[0058] Example 8:

[0059] Based on Example 7, in step (7), a correction frequency rule base (Table 4) and a compensation time rule base (Table 5) were established by dynamically collecting the position, speed, and thrust of the two push link heads using a fuzzy control algorithm. Furthermore, the off-center load judgment of the push chain device lifting platform is related to multiple variables, among which the position difference x and thrust difference f of the two push link heads are the most critical factors in determining whether the push chain device lifting platform is off-center. Therefore, an off-center load judgment rule base (Table 6) was established by combining these two variables.

[0060] Example 9:

[0061] Based on Embodiment 8, in step (8), in order to achieve synchronous operation of the two push chain devices and eliminate the positional deviation of the two push chain devices, the correction frequency of the slave motor M2 is calculated by inferring from the correction frequency rule base. The compensation frequency of motor M2 =Operating frequency of main motor M1 +Correction Frequency The compensation time of motor M2 is inferred using the compensation time rule base. That is, the operating time of the motor at its compensated frequency.

[0062] Example 10:

[0063] Based on Example 8, the off-center load inference rule base established in step (8) is compared and judged to determine when the off-center load parameters of the lifting platform are... When the lifting platform is not eccentrically loaded, it is determined that the lifting platform is not eccentrically loaded; when the lifting platform's eccentricity parameter... When the lifting platform is under uneven load, the motor M2 first automatically eliminates the uneven load through compensation frequency and compensation time. If the uneven load cannot be eliminated, the lifting platform will alarm and stop. Here, P0=3 is the uneven load judgment benchmark calculated based on experience.

[0064] The rule base for the fuzzy algorithm involved in this invention is shown in the table below:

[0065] Table 4 Correction Frequency Rule Base

[0066]

[0067] Table 5 Compensation Time Rule Base

[0068]

[0069] Table 6 Off-center load inference rule base

[0070]

[0071] With the above configuration, the present invention has the following advantages:

[0072] (1) The lifting platform of this push chain device can lift heavy loads. The platform is more stable during the lifting process and has a longer service life. It realizes synchronous control and off-center load detection of the lifting platform.

[0073] (2) The lifting platform of this push chain device can realize reciprocating lifting under heavy load and extra heavy load.

[0074] (3) The lifting platform of this push chain device realizes the synchronous control of two three-phase motors through the fuzzy rule library, which greatly reduces the control cost.

[0075] (4) The lifting platform of this push chain device has strong robustness and can achieve good synchronous control under different working conditions.

[0076] (5) The lifting platform of this push chain device uses tension and pressure sensors to read the thrust of the push chain device and realize the off-center load alarm detection of the lifting platform.

[0077] (6) By optimizing the operation of the two push chain devices, the service life of the lifting platform was extended.

[0078] (7) The lifting platform of this push chain device has high real-time responsiveness and can quickly eliminate the position deviation of the lifting platform.

[0079] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in this patent.

Claims

1. A control method for synchronous operation of a dual-push chain lifting platform, characterized by comprising the following steps: (1) Detect the position of the push link heads of the two push chain devices; (2) Calculate the velocities of the two push chains; (3) Calculate the position difference between the headers of the two push links; (4) Read the push force of the two push link headers; (5) Calculate the thrust difference between the two push links; (6) Determine the off-load status based on the fuzzy rule base and calculate the compensation frequency and compensation time.

2. The control method for synchronous operation of a dual-push chain device lifting platform as described in claim 1, characterized in that, In step (1), each of the two push chain devices is equipped with a three-phase motor as a drive motor, namely three-phase motor M1 and three-phase motor M2. Each three-phase motor is equipped with an independent frequency converter for drive. Three-phase motor M1 is the main motor and three-phase motor M2 is the slave motor. The speed, position and thrust of the main motor are the reference. The positions x1 and x2 of the push chain device are detected by the encoder of the three-phase motor.

3. The control method for synchronous operation of a dual-push chain device lifting platform as described in claim 2, characterized in that, In step (2), the position x of the push link header is collected at time intervals T. 11 and x 12 x 21 and x 22 Calculate the speed of the push chain device joint. and .

4. The control method for synchronous operation of a dual-push chain device lifting platform as described in claim 3, characterized in that, In step (3), the position difference between the joints of the two push chain devices is x = x2 - x1.

5. The control method for synchronous operation of a dual-push chain device lifting platform as described in claim 4, characterized in that, In step (4), the push chain heads output by the two push chain devices are connected to the bottom of the platform through tension and pressure sensors, and the two tension and pressure sensors detect the thrust f1 and f2 of the two push chain device joints.

6. The control method for synchronous operation of a dual-push chain device lifting platform as described in claim 5, characterized in that, In step (5), the thrust difference between the two push chains is f = f2 - f1.

7. The control method for synchronous operation of a dual-push chain device lifting platform as described in claim 6, characterized in that, In step (6), based on the fuzzy control algorithm, the position, speed and thrust of the two push link heads are dynamically collected, and the compensation frequency and compensation time of the frequency converter are inferred according to the fuzzy rule base based on two-dimensional variables.

8. The control method for synchronous operation of a dual-push chain device lifting platform as described in claim 7, characterized in that, In step (6), in order to achieve synchronous operation of the two push chain devices and eliminate the positional deviation of the two push chain devices, a correction frequency rule library and a compensation time rule library are established respectively based on the operating experience of the push chain devices; the correction frequency of the slave motor M2 is inferred and calculated through the correction frequency rule library, and the compensation frequency of the slave motor M2 is further calculated; the compensation time of the slave motor M2 is inferred through the compensation time rule library.

9. The control method for synchronous operation of a dual-push chain device lifting platform as described in claim 8, characterized in that, In step (6), an off-center load inference rule base is established based on the position difference x and the thrust difference f to determine the state of the lifting platform. When the lifting platform is in an off-center load state, the off-center load is automatically eliminated by the compensation frequency and compensation time. If the off-center load cannot be eliminated, the lifting platform will alarm and stop.

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