Double-layer vibration table frequency division driving strategy

Abstract

The invention discloses a double-layer vibration table frequency division driving strategy which comprises a target signal, a vibration table controller, an upper-layer vibration table, a lower-layer vibration table, a test substructure and an accelerometer. The vibration table controller comprises an offline iteration module, a frequency division strategy, an upper layer PID control algorithm, a lower layer PID control algorithm, an upper layer pressure difference control algorithm and a lower layer pressure difference control algorithm. The off-line iteration comprises a stage I-system identification process and a stage II-iteration process, the target signal is input into an off-line iteration module in the vibration table controller, and a driving signal is calculated through the off-line iteration module. According to the frequency division driving strategy of the double-layer vibration table, the excitation of the vibration table is divided into an upper layer and a lower layer to be respectively controlled through an offline iterative algorithm, the reproduction of the vibration table on high-frequency excitation can be met, and the test requirements of the structure are met.

Description

Technical field:

[0001] The invention relates to the technical field of control methods, and in particular to a frequency division driving strategy for a double-layer vibration table. Background technology:

[0002] For large vibration tables with a payload of more than 1,000 tons, the typical operating frequency range is 0-30Hz. For rigid engineering structures such as water conservancy projects and nuclear power facilities, their scaled models have a higher fundamental frequency, and the operating frequency range of large vibration tables is difficult to meet the test requirements of these structures. To address this problem, a new engineering solution is proposed. A high-frequency vibration table is installed on top of a low-frequency vibration table to form a double-layer vibration table system. In this system, the low-frequency vibration table has a larger stroke to reproduce the displacement and velocity signals in the low-frequency range, while the high-frequency vibration table has a shorter stroke to reproduce the high-frequency acceleration signal. This strategy can achieve large displacement and wide-band excitation of large vibration tables. Due to the strong interaction between the two vibration tables, the control difficulty of this double-layer table system is relatively high. A frequency division control strategy based on offline iterative control is proposed to drive the double-layer vibration table system. Summary of the invention:

[0003] To achieve the above objectives, the present invention is implemented through the following technical solutions: a double-layer vibration table frequency division driving strategy, including a target signal, a vibration table controller, an upper vibration table, a lower vibration table, a test substructure and an accelerometer;

[0004] The vibration table controller includes an offline iteration module, a frequency division strategy, an upper PID control algorithm, a lower PID control algorithm, an upper pressure difference control algorithm, and a lower pressure difference control algorithm;

[0005] The offline iteration includes phase I - system identification and phase II - iteration process.

[0006] Preferably, the target signal is input into an offline iteration module inside the vibration table controller, the drive signal is calculated by the offline iteration module, and then the drive signal is divided into an upper drive signal and a lower drive signal required by the upper vibration table and the lower vibration table using a frequency division strategy.

[0007] Preferably, the upper-layer drive signal adopts an upper-layer PID control algorithm and an upper-layer pressure difference control algorithm, and the lower-layer drive signal adopts a lower-layer PID control algorithm and a lower-layer pressure difference control algorithm. At the same time, an accelerometer is used to measure the corresponding acceleration and feed it back to the offline iteration module for iterative calculation.

[0008] Preferably, the offline iteration module is divided into two stages: stage I-system identification and stage II-iterative process. In stage I, the double-layer vibration table including the frequency division strategy is regarded as a whole, and the transfer function matrix H of the double-layer vibration table is identified according to the relationship between input and output. Once the transfer function inverse matrix G is determined, the 14-stage II iterative process is started to compare the target signal w0 with the corresponding response y m The difference uses the transfer function inverse matrix G to update the drive signal u UST and u LST , to reproduce the target signal w0.

[0009] The present invention provides a frequency division driving strategy for a double-layer vibration table. It has the following beneficial effects:

[0010] The double-layer vibration table frequency division driving strategy divides the vibration table excitation into upper and lower layers and controls them separately through an offline iterative algorithm, which can satisfy the vibration table's reproduction of high-frequency excitation and meet the test requirements of the structure. Description of the drawings:

[0011] Figure 1 It is a structural diagram of the frequency division offline iterative control method of the double-layer vibration table of the present invention;

[0012] Figure 2 This is a structural diagram of the vibration table controller of the present invention;

[0013] Figure 3 This is a structural diagram of the offline iteration module of the present invention.

[0014] In the figure: 1. Target signal; 2. Vibration table controller; 3. Upper vibration table; 4. Lower vibration table; 5. Test substructure; 6. Accelerometer; 7. Offline iteration module; 8. Frequency division strategy; 9. Upper PID control algorithm; 10. Lower PID control algorithm; 11. Upper pressure difference control algorithm; 12. Lower pressure difference control algorithm; 13. Phase I - system identification; 14. Phase II - iteration process. Specific implementation method:

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0016] See also Figure 1-Figure 3The present invention provides a technical solution: a double-layer vibration table frequency division driving strategy, the test substructure is installed on the upper vibration table, and is excited by the upper vibration table and the lower vibration table at the same time, the target signal w0 is input into the offline iteration module, the driving signal u is calculated, and then the driving signal u is divided into the driving signal u required by the upper vibration table and the lower vibration table by using the frequency division strategy UST and u LST ;

[0017] The upper vibration table adopts upper proportional-integral-differential control (PID) and upper pressure difference control, and the lower vibration table adopts lower proportional-integral-differential control (PID) and lower pressure difference control;

[0018] The acceleration corresponding to the target motion measured by the upper vibration table is recorded by the accelerometer and fed back to the offline iteration module for iterative calculation;

[0019] In the stage I system identification, the double-layer vibration table including the frequency division strategy is considered as a whole, and the transfer function matrix H of the double-layer vibration table is identified according to the relationship between input and output;

[0020] Once the inverse transfer function matrix G is determined, the phase II iteration process is started to compare the target signal w0 with the corresponding response y m The difference uses the transfer function inverse matrix G to update the drive signal u UST and u LST , to reproduce the target signal w0;

[0021] Due to the strong interaction between the upper and lower shaking tables, the proposed off-line iterative method for the double-layer shaking table is different from the combination of the off-line iterative methods of two independent shaking tables, whose transfer function matrix H is coupled together.

[0022] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without creative work should fall within the scope of protection of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention are implemented according to the conventional means in the field unless otherwise specified and limited.

Claims

1. A double-layer vibration table frequency division driving strategy, characterized in that: It includes 1-target signal, 2-vibration table controller, 3-upper vibration table, 4-lower vibration table, 5-test substructure and 6-accelerometer; The vibration table controller includes 7-offline iteration module, 8-frequency division strategy, 9-upper layer PID control algorithm, 10-lower layer PID control algorithm, 11-upper layer pressure difference control and 12-lower layer pressure difference control algorithm; The offline iteration includes 13-stage I-system identification and 14-stage II-iterative process.

2. A double-layer vibration table frequency division driving strategy according to claim 1, characterized in that: The 1-target signal is input into the 2-offline iteration module inside the vibration table controller, the driving signal is calculated by the 7-offline iteration module, and then the driving signal is divided into the upper driving signal and the lower driving signal required by the upper vibration table and the lower vibration table using the 8-frequency division strategy.

3. A double-layer vibration table frequency division driving strategy according to claim 2, characterized in that: The upper-layer driving signal adopts 9-upper-layer PID control algorithm and 11-upper-layer pressure difference control algorithm, and the lower-layer driving signal adopts 10-lower-layer PID control algorithm and 12-lower-layer pressure difference control algorithm. At the same time, 6-accelerometer is used to measure the corresponding acceleration and feed it back to 7-offline iteration module for iterative calculation.

4. A double-layer vibration table frequency division driving strategy according to claim 3, characterized in that: The 7-offline iteration module is divided into two stages: 13-stage I-system identification and 14-stage II-iterative process. In 13-stage I, the double-layer vibration table including the frequency division strategy is regarded as a whole, and the transfer function matrix H of the double-layer vibration table is identified according to the relationship between input and output. Once the transfer function inverse matrix G is determined, the 14-stage II iterative process is started to compare the target signal w0 with the corresponding response y m The difference uses the transfer function inverse matrix G to update the drive signal u UST and u LST , to reproduce the target signal w0.

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