JP3337392B2 - Vibration motion generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration operation generating device for generating a vibration operation in, for example, a wave making device.

[0002]

2. Description of the Related Art Conventionally, for example, when a wave making test is performed in a water tank or the like, a wave is generated in the water tank using a wave making device. The wave-making device has a structure in which a lower portion of the wave-making plate is rotatably provided by positioning the lower portion of the wave-making plate on the water surface, and the upper portion of the wave-making plate is connected to a driving device and vibrated to generate waves. . A conventional control device for driving the wave-making device is generally configured as shown in FIG. In FIG. 5, 101 is a computer, 102 is its memory,
A plurality of analog output devices 103 are connected to the computer 101. An amplifier 104 is connected to each of the analog output devices 103, and a plurality of driving devices 105 are connected to each of the amplifiers 104. Each of the amplifying devices 104 includes a plurality of amplifiers corresponding to each of the driving devices 105.

[0003] The control device of the above-mentioned conventional wave-making apparatus previously calculates and obtains a wave-making signal for generating a desired wave by the computer 101 or a completely different computer, and stores it in the memory 102. The stored wave signal is sent to the analog output device 103 at regular intervals at regular intervals. Here, the signal is converted into an analog signal for operating the driving device 105, and is amplified via the amplifier 104 to a power enough to operate the driving device 105. As a result, a plurality of driving devices 1
05 operate independently based on a desired wave-forming signal. With the wave-making plate attached to the driving device 105, for example, water in a water tank can be moved to generate a wave.

[0004]

When an irregular wave having a desired spectrum is generated in a water tank by a wave making device, a wave plate of the wave making device is calculated from the irregular wave having a desired spectrum. A low-frequency component wave constituting an irregular wave signal propagates on the water surface faster than a high-frequency component wave. For this reason, the motion of the wave plate itself has a desired spectrum, but at the measurement point where the device under test is installed, the wave arrives from a low frequency component wave, and for a while after the start of wave making, the desired spectrum is obtained. Not only that, but the DUT only responds to the low frequency components that it reaches first,
Even after the desired spectrum is obtained, this response will adversely affect the test data.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. When a wave arrives at a measurement point where a device under test is installed, the irregular wave is formed so as to have a desired spectrum as an irregular wave. It is an object of the present invention to provide a vibration operation generating device capable of controlling a generation time of a plurality of regular waves constituting a plurality of regular waves to generate in real time and generating a wave command signal.

[0006]

A vibration operation generating apparatus according to the present invention includes a computer for performing a preliminary calculation for obtaining a desired vibration operation, a plurality of driving devices for operating a vibration object, and
A plurality of motion control devices that calculate unsteady and steady state operation command values in real time based on the parameters obtained in the preliminary calculation, and smoothly control the driving device according to the command values; A system control device that generates a synchronization signal at a constant period, outputs the synchronization signal to each of the motion control devices via a digital output device, and synchronizes the plurality of motion control devices; and the computer, the motion control device, and the system control. A network transmission line connecting the devices, the motion control device calculates a wave-making command signal in real time according to parameters sent from the computer, and generates the wave-making command signal and a function generator. A command value calculation device that outputs an actual wave-making signal command value by calculation with a function, and a wave-making signal command value output from the command value calculation device is compared with the position signal of the vibration target, A control operation device that outputs a control signal for controlling a difference between the wave signal command value and the position signal of the vibration target to be zero, and a control signal output from the control operation device is a synchronization signal from the system control device. And an output device for outputting to the driving device in synchronization with the driving device.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration example when the present invention is applied to a control device of a wave making device.
In FIG. 1, reference numeral 1 denotes a computer for a preliminary calculation, which performs a preliminary calculation according to what kind of wave-making is to be performed, and transmits a parameter obtained as a result via a network transmission line 7 to a system controller 2 and a plurality of motion controllers. 3 The network transmission path 7 is terminated by a terminating resistor 6. An amplification device 4 is connected to each of the motion control devices 3, and a plurality of driving devices 5 are connected to each of the amplification devices 4. Each of the plurality of driving devices 5 drives the wave-making plate.

[0010] The system control device 2 comprises a network connection device 21, an operation device 22 and a digital output device 23 as shown in FIG. System control unit 2
Outputs the parameters sent from the computer 1 via the network transmission path 7 to the arithmetic unit 22 and the digital output unit 23. Further, the arithmetic unit 22 generates a synchronization signal at regular intervals at regular intervals, outputs the synchronization signal to each of the motion control devices 3 via the digital output device 23, and operates the plurality of motion control devices 3 in synchronization.

As shown in FIG. 3, the motion control device 3 includes a network connection device 31, a control calculation device 32, a command value calculation device 33, a function generation device 34, a timer 35, and a counting device 36 for reading the position of the wave plate. , Analog output device 3
7. It consists of a digital input device 38. In the motion control device 3, the parameters transmitted from the computer 1 via the network transmission path 7 are received by the network connection device 31 and input to the command value calculation device 33. The command value calculation device 33 calculates the wave signal command value in real time according to the parameters obtained by the preliminary calculation of the computer 1. The calculated value is multiplied by the output from the function generator 34 to provide an actual wave signal command value, which is sent to the control arithmetic unit 32. The timer 35 determines a transient state, that is, a timing of addition when adding the frequency components one by one when the command value calculation device 33 calculates the wave signal instruction value. The wave making signal command value indicates a command value of the position of the wave making plate.

The control arithmetic unit 32 compares the wave signal command value input from the command value arithmetic unit 33 with the position signal of the wave plate read by the counter 36, and compares the wave signal signal value with the wave signal signal value. A digital signal for controlling the “wave plate position signal” to be zero is sent to the analog output device 37. The analog output device 37 converts the received digital signal into an analog signal and outputs the analog signal to the amplifier 4. The timing for outputting to the amplifying device 4 is such that the arithmetic unit 22 of the system control device 2 outputs a synchronization signal at regular intervals at regular intervals,
This is performed by being input to the digital input device 38 of the exercise control device 3 via the digital output device 23.

The analog signal output from the analog output device 37 is sent to the amplifier 4 and amplified. As shown in FIG. 4, the amplifying device 4 includes a plurality of amplifiers 41 provided corresponding to the respective driving devices 5, and amplifies the signal from the analog output device 37 into power capable of driving the driving device 5 by the amplifier 41. I do.

Next, a preliminary calculation performed by the computer 1 and a command value calculation device 33 of the motion control device 3 and a function generation device 34
The contents of the real-time calculation executed by the timer 35 will be described by taking as an example a case where a multidirectional irregular wave is generated.

The time step of the i-th wave plate attached to the driving device 5 (a time interval for continuously processing digital signals, which is set independently of the wave cycle)
j is the wave-forming signal command value η _ij

[0014]

(Equation 1) It is represented by Here, n: number of the frequency component of the irregular wave, numbered from the lowest frequency m: number of the direction component of the irregular wave N: number of frequency components of the irregular wave M: number of direction components of the irregular wave a _nm: n-th frequency component, the amplitude of the m-th direction component F _n: n-th wave characteristic function of a frequency component [pi: pi f _n: n-th frequency Delta] t: control period k _n: n-th The wave number b of the frequency component of b: the width of the wave plate θ _m : the m-th direction angle ε _nm : the random number of the n-th frequency component and the m-th direction component. First, a steady-state real-time wave-making algorithm when j is sufficiently large will be described.

[0015]

(Equation 2) お き_nij = ξ _ni cos (j · 2π · f _n · Δt) + ζ _ni sin (j · 2π · f _n · Δt) (4) Φ _nij = ζ _ni cos (j · 2π · f) _n · Δt) −ξ _ni sin (j · 2π · f _n · Δt) (5), the following iterative calculation formula is obtained.

Ψ _{ni, j + 1} = α _n ψ _nij + β _n Φ _nij (6) Φ _{ni, j + 1} = α _n Φ _nij −β _n ψ _nij (7) where α _n = cos (2π · F _n · Δt) (8) β _n = sin (2π · f _n · Δt) (9) Eventually, when j is sufficiently large, the steady-state wave-making signal command value η _ij is

[0017]

(Equation 3) Is required. Further, the time step j + 1 wave generation signal command value η _{i, j + 1} is

[0018]

(Equation 4) Where the right side of equation (11) can be obtained from equations (6) and (7) by using the calculation result of time step j.

FIG. 8 shows a flowchart of the above-described steady-state real-time wave-making algorithm. That is, step A1 is a preliminary calculation step based on the above equations (2) and (3). After the preliminary calculation, "j = j" is set (step A2), and the real-time calculation is performed (step A).
3). This real time calculation is based on the above (6), (7) and (1)
This is performed according to equation (0). The real time calculation is performed in step A4.
Is repeated while the value of j is set to "+1". Through the above processing, the steady-state real-time wave signal command value η _ij is obtained.

The above is an algorithm in a steady state, and if this algorithm is used as it is from the wavemaking start time, the problem to be solved by the present invention cannot be solved. Therefore, the algorithm in the transient state described below is executed at the start of wave making.

The time required for the frequency component of the irregular wave f _n to reach the measurement point where the device under test is installed is t = 4πdf _n / g sin θ (12). The above equation takes the group velocity as the velocity of the traveling wave of water, and takes the group velocity assuming that it is a deep water area, and the assumption of the deep water area is appropriate in a commonly used seaworthy tank. Here, g: gravitational acceleration d: linear distance from the front surface of the wave-making plate 52 in the water tank 51 shown in FIG. 6 to the measurement point A where the device under test is placed θ: representative direction in which the multidirectional irregular wave travels The angle is taken as shown in FIG. FIG. 6 is a conceptual diagram of the angle θ taken by the traveling wave 53 generated by the wave plate 52 provided in the water tank 51.

Here, the next time is defined. t _Ni = t _{f, N} −t _{f, i} (13) That is, the difference between the time when the highest frequency component (N) reaches the measurement point minus the time when the i-th frequency component reaches the measurement point. _Is t _Ni .

The basic idea is to start the wave generation from the highest frequency component so that the waves of the respective frequency components reach the measurement point at the same time, and multiply the time difference of equation (13) to generate the low frequency component. And add it to the higher frequency components.

First, after the start of wave making, that is, when j = 1, only the highest frequency component (N) is output as the wave making signal command value η _ij . The calculation formula is as _follows : α _Nij = α _N ψ _{Ni, j-1} + β _n Φ _{Ni, j-1} ... (14) Φ _Nij = α _N Φ _{Ni, j-1} + β _n ψ _{Ni, j-1} ... (15) η = _ψNij, f _fade (16) Until the time t ₁ Komu adding next higher frequency component (N-i) (14) , (15), repeating (16). Here, f _fade is a function shown in FIG. 7, and is a function for preventing the output from bumping (jumping) when adding a new frequency component. By multiplying the above-mentioned f _fade , it is possible to smoothly change the command value of the wave-making signal. Then, if the time t _1, Komu plus the next higher frequency component (N-1). That is, ψ _nij = α _n ψ _{ni, j-1} + β _n Φ _{ni, j-1} , n = N-1, N... (17) Φ _nij = α n Φ _{ni, j-1} + β _n ψ _{ni, j- 1} , n = N-1, N (18) η _ij = η _ij + ψ _{N-1, ij.f fade} (19)

Hereinafter, similarly, it is sufficient to add up to the lowest frequency component. After that, the steady-state algorithms (6), (7), and (8) may be executed. FIG. 9 shows a flowchart of the present algorithm.

That is, a preliminary calculation is performed in step B1,
Real-time calculation is performed after step B2. This real-time calculation includes calculation of the transient state in steps B2 to B10 and calculation of the steady state in steps B11 and B12.

After performing the preliminary calculation in step B1, after performing the processes of "nn = 0" (step B2), "η _ij = 0" (step B3), and "j = 1" (step B4) , (17), (18), and (19) are calculated (step B5).

Thereafter, a determination process of “t _{nn + 1} ≧ j · Δt” is performed (step B 6), and “t _{nn + 1”} is changed to “j · Δt”.
If smaller, the value of j is incremented by "+1" (step B
7) Then, the process of step B5 is executed again. If “t _{nn + 1”} is equal to or larger than “j · Δt”, “j = j +
1 (step B8) and the process of "nn = nn + 1" (step B9) are performed, and it is determined whether "nn" is equal to or more than "N-1" (step B10). "Nn" becomes "N-
If it is smaller than "1", the process returns to step B5.

If "nn" is equal to or larger than "N-1", a steady state process is executed according to the equations (6), (7) and (11) shown in step B11. The process of step B11 is repeatedly performed while sequentially increasing the value of “j” by “+1” in step B12.

FIG. 10 shows a water tank 51 of FIG.
0m, width 30m, depth 3.5m, width 30
m, a significant wave height of 0.1 m and a significant frequency of 0.67 sec in the ISSC type spectrum by the multi-segment wave generator installed on the m side.
c, and the measurement point A is set at 46.8 m from the wave plate 52.
5 shows the acquired data when the is installed.

FIG. 10 shows time-series data of wave heights obtained at a measurement point A, which is made by a conventional technique. This figure 1
At 0, it can be seen that the wave of the low frequency component has arrived early.

FIG. 11 shows time-series data when waves are created by the apparatus of the present invention. In this FIG.
It can be seen that the waves arrive at ec at the same time. FIG. 12 and FIG. 13 show time and frequency analyzes of these data using the wavelet transform. FIG. 12 shows FIG.
0, and FIG. 13 corresponds to FIG. FIG.
It can be clearly understood that it has reached from the low frequency component. On the other hand, in FIG. 13, it can be seen that the desired spectrum is obtained from the beginning.

[0033]

As described above in detail, according to the present invention, the calculation of the operation command value for the vibration object is separated into a preliminary calculation and a real-time calculation, and the real-time calculation is performed by the motion control device and determined in advance. The operation command value can be calculated while controlling the driving device that drives the vibration target without calculating the wave-forming signal at the given time.

Therefore, at any measurement point where the DUT is placed in the water tank, a wave-making command value can be calculated in real time so that a desired spectrum wave arrives from the start of the experiment.
Experiments can be performed efficiently and accurate experimental data can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of a vibration operation generating device according to an embodiment of the present invention.

FIG. 2 is an exemplary block diagram showing the configuration of a system control device according to the embodiment;

FIG. 3 is an exemplary block diagram showing a configuration of a motion control device according to the embodiment.

FIG. 4 is a block diagram showing the configuration of the amplification device according to the embodiment.

FIG. 5 is a block diagram showing a configuration of a control device of a conventional wave making device.

FIG. 6 is a conceptual diagram of an angle taken by a traveling wave in a water tank.

FIG. 7 is a diagram showing a function for obtaining a smooth wave-making signal command value.

FIG. 8 is a diagram showing a flowchart of a real-time wavemaking algorithm in a steady state.

FIG. 9 shows a flowchart of a transient state and steady state real time algorithm according to the present invention.

FIG. 10 is a diagram showing time-series data of wave heights obtained at measurement points by wave-making by a conventional technique.

FIG. 11 is a diagram showing time-series data of wave heights obtained at measurement points by making waves by the apparatus of the present invention.

FIG. 12 is a diagram showing a time / frequency analysis obtained by performing the wavelet transform on the data of FIG. 10;

FIG. 13 is a diagram showing a time / frequency analysis obtained by performing the wavelet transform on the data of FIG. 11;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 computer 2 system control device 3 motion control device 4 amplifying device 5 drive device 6 terminating resistor 7 network transmission line 21 network connection device 22 calculation device 23 digital output device 31 network connection device 32 control calculation device 33 command value calculation device 34 function Generator 35 Timer 36 Counting device 37 Analog output device 38 Digital input device 41 Amplifier 51 Aquarium 52 Wave plate 53 Traveling wave

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masafumi Umeda 60-1 Kutsubo, Iwazuka-cho, Nakamura-ku, Nagoya-shi, Aichi 1 Churyo Engineering Co., Ltd. In-house (56) References A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G01M 10/00 G05D 19/02

Claims (1)

(57) [Claims] 1. A computer for performing a preliminary calculation for obtaining a desired vibration operation, a plurality of driving devices for operating an object to be vibrated, and a non-stationary and a stationary in real time based on parameters obtained in the preliminary calculation. A plurality of motion control devices that calculate the operation command value of the state and smoothly control the drive device according to the command value, generate a synchronization signal at a constant period at regular time intervals, and output the synchronization signal via a digital output device. A motion control device that outputs to the motion control device and synchronizes the motion control devices; and a network transmission line connecting the computer, the motion control device, and the system control device. Calculates the wave-making command signal in real time according to the parameters sent from and outputs the actual wave-making signal command value by calculating the wave-making command signal and the function generated by the function generator. A command value calculation device that,
A control signal for comparing a wave signal command value output from the command value calculating device with the position signal of the vibration target, and controlling the difference between the wave signal command value and the position signal of the vibration target to be zero. And an output device for outputting a control signal output from the control operation device to the drive device in synchronization with a synchronization signal from the system control device. apparatus.