KR20080019342A - Method for analysis of object movement in construction graphical simulation system - Google Patents

Abstract

A method for analyzing movement of objects in a graphic construction simulation system is provided to secure stability about equipment management and improve construction ability in a construction field by linking a physical model with a graphic model for movement of a pulley and rotation of a boom in a tower crane. A physical model type of a crane is established to classify movement of objects into each group(S10). A movement equation is extracted for each physical model type by using Lagrange equation(S12). The movement equation of each model is stored in a file(S14). The file is loaded to a VR(Virtual Reality) simulation device by using a script(S16). The movement of the object is visualized according to work progress by linking with a graphic object in a program of the VR simulation device(S18). The movement equation established by the Lagrange equation is numerically analyzed by using Runge-Kutta analysis.

Description

{METHOD FOR ANALYSIS OF OBJECT MOVEMENT IN CONSTRUCTION GRAPHICAL SIMULATION SYSTEM}

1 is a view showing the force and the action of the movement of the object in the crane system applied to the present invention,

2 is a view of the motion analysis procedure of the crane applied to the present invention,

3 is a view showing the cable shake when moving only the pulley in the crane applied to the present invention,

4 is a view related to the shaking of the cable during the rotation of the boom in the crane applied to the present invention,

5 is a view of the cable shake during pulley movement and boom rotation in the crane applied to the present invention,

6 is a view showing an example of an acceleration profile for a pulley of a crane applied to the present invention,

7 is a graph of the position and the speed of the pulley of the crane applied to the present invention,

8 is a graph of the swing angle and the angular velocity of the crane cable applied to the present invention,

9 is a flowchart of a method for simulating the movement of a crane cable according to the present invention;

10 is a view for explaining the target of the motion graphics object for each part of the crane applied to the present invention,

11A to 11D are diagrams showing visually showing the propulsion of the crane cable in the virtual reality simulation apparatus according to the present invention as the time-based movement.

The present invention relates to motion analysis of construction equipment, and more particularly, to a method for analyzing the movement of objects in a construction simulation system.

Current construction graphic simulation systems do not include models that reflect the physical properties of construction equipment and materials. In general, it is necessary to analyze the physical characteristics such as load, speed, and acceleration of construction equipment and materials in order to simulate the construction process similarly to reality through graphic simulation including the physical model. Prior studies related to this suggest the necessity of a physical model for virtual reality construction simulation, and summarized theoretical studies to be accompanied by the basic research necessary to reflect the physical model in construction equipment graphic simulation. have. However, in order to consider physical phenomena such as deformation of the equipment, ground conditions, and weather conditions for graphic simulations reflecting physical modeling, if the modeling process is actually time-consuming and complicated modeling process is required, real-time analysis is not available. The reality of graphic simulation reflecting this is reduced. However, despite the difficulties associated with such physical modeling, construction processes such as crane work, ie the propulsion of cables and materials that appear when the crane boom is moved, must be considered simultaneously in order to improve workability and safety of work. There are cases where implementation is possible. As a study on the propulsion of a similar crane cable, we refer to methods for organizing and controlling studies on the physical modeling of crane cables.

As a result of analyzing the characteristics of physical modeling to improve the function of graphic simulation based on the previous research results, it was considered unrealistic to pursue the complete physical modeling and analysis that can consider the ground, weather and deflection.

And, the fixed material is fixed at the end of the equipment, but the geometric analysis without consideration of the physical model can make a sufficient contribution to the confirmation of the possibility of collision between the equipment and the material in the narrow space and the possibility of construction. In the case of crane, which is the most representative equipment for handling a fixed object, the cable is used, there is a problem in that the dynamic behavior related to the propulsion drive must be considered at the same time in the geometric analysis.

The present invention is to solve the above problems, an object of the present invention is to be fixed to the end of the object, such as the propulsion movement in the construction equipment virtual reality simulation system to predict the movement in consideration of the collision due to the movement, etc. To provide a method of interpretation.

In the construction graphic simulation system according to the present invention for realizing the above object, the motion analysis method of the object comprises the steps of establishing the physical model form of the crane to distinguish the object movement by the same group; In the step of establishing the model form, deriving a motion equation for each divided form; If the equations of motion are derived for each model, storing them in a corresponding file; Loading the file using a script; And visualizing the movement of the object as the work progresses by connecting to the graphic object on the virtual reality simulation device program.

In the step of establishing the physical model form of the crane in order to distinguish the movement of the object by the same group, it characterized in that it is divided into the case of moving independently for each object, and the case of moving the objects together.

In the step of deriving the equation of motion for each of the divided forms, it is characterized by deriving the equation of motion using the Lagrange equation.

The equation of motion established by the Lagrange method is characterized by numerical analysis using the Runge Kutta solution.

In the storing of the corresponding file, the exercise analysis result is stored as a text file.

The motion analysis result stored in the text file is visualized in connection with a graphic object in a virtual reality program using a script.

The virtual reality program is characterized in that the program that supports the object-oriented environment for interaction between the graphical objects.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings that can be easily implemented by those skilled in the art.

In the present invention, when the crane system, which is generally used in the construction site, reaches the point where the lifting material reaches the target point, the workers are dismantled and dismantled the object from the cable. The construction of the material connected to the target structure, and for this work, the crane operator means a task that focuses on minimizing the shaking of the member when the lifting member is near the target point and close to the workers in the field.

In this work the physical modeling scope of the crane is the propulsion of the cable.

The motion model for the motion analysis of the propulsion crane of crane is presented by considering the pulley movement only, the boom rotation only and the boom rotation and the pulley movement. By suggesting an improved construction graphic simulation method through linkage between the physical model and the graphic model, and by describing the construction state using the crane in this way, the optimal position of the crane is selected and the number of cranes required accordingly. The purpose of this study is to improve construction productivity by securing construction stability and reduction of human or material loss caused by accidents caused by propulsion of crane cable by helping to decide the operation method.

First, the physical modeling necessary to simulate the dynamic movement of a crane is described. Cranes using cables can usually be represented by a cart-pendulum system.

1 is a view showing the movement of the free body of the crane system. Referring to Figure 1, through the mechanical analysis of the pulley connected to the cable and the suspended object it is possible to obtain a motion equation for the position of the pulley and the angle of the cable swing. The results derived from this will be used to model the shaking of the crane cable.

The equation of motion of the crane can be expressed in the form of the following equations in the free body diagram of FIG. 1 based on Newton's method.

Where M is the mass of the pulley and m is the mass of the suspended object.

R: cable length, T: cable tension, x: location of pulley

θ: shake angle, F: pulley force

F _t : the right hand force caused by the shaking resistance of the object,

g: acceleration of gravity

First of all, it is necessary to distinguish three types of movements of the cranes for the motion analysis of the cranes, when only the boom is rotated without the pulleys, and when the pulleys and the booms rotate simultaneously. The kinematic equation for the kinematic analysis uses Newton's method, which is a general kinematic equation solution, but this newton method is more complicated than Lagrange's method of scalar calculation using velocity because it requires acceleration and uses vectors. In addition, when three-dimensional analysis is involved, such as the propulsion of a crane cable, the equilibrium equation must be established by considering all the forces acting in each direction by using Newton's method.

In the present invention, the motion equation is divided by using the Lagrange method in consideration of speed, acceleration, and the like for each motion type.

The Runge Kutta solution is applied to the numerical analysis of the equations of motion of cranes established by the Lagrange method.

The Runge-Kutta method is derived from the Taylor method and is suitable for general use because it is very accurate, stable, and easy to implement in a program. Most experts argue that there is no need to use higher order methods because the benefits of increased accuracy are offset by the additional computation required. Therefore, if you want to get a more accurate value, you must either make the gap smaller or use an adaptive method.

The movement form of the crane can be divided as shown in FIG.

It is a figure regarding the motion analysis form of the crane applied to this invention.

First, when only the pulley moves, only the shaking of the cable with respect to the linear motion of the pulley moving by hanging on the boom of the crane. In this case, the crane using the cable appears as shown in FIG.

Figure 3 is a view showing the cable shake when moving only the pulley in the crane applied to the present invention. As shown, the dynamic equations of the pulley to which the cable is connected and the suspended object also provide the equations of motion regarding the position of the pulley and the angle at which the cable swings. In the present invention, the Lagrange method of scalar calculation using velocity is used. This part will be described later.

The crane system in the case of the pulley only moves, as shown in FIG. 3, the distance from the vertical central axis of the crane to the pulley is R, the swing angle of the crane cable is α _R , and the mass of the pulley and the suspended object is M, respectively. And m, the length of the cable can be represented by L.

First, in order to develop the Lagrange equation, it is necessary to calculate the kinetic energy and potential energy of the system as shown in the following equation, and for this purpose, the positions and velocities of Table 1 and Table 2 should be considered.

Pulley position and speed X ₁ = R V _X1 = R ′ Y ₁ = 0 V _Y1 = 0 Z ₁ = 0 V _Z1 = 0

The position and velocity of the object X ₂ = R + Lsinα _R V _X2 = R + Lα _R ′ cosα _R Y ₂ = 0 V _Y2 = 0 Z ₂ = -Lcosα _R V _Z2 = Lα _R ′ sinα _R

From the Lagrangian equations for the general coordinates Rα _R in the above equations, the equations of motion are developed.

Using the Lagrange equation, two equations of motion were obtained for the location of the pulley and the swing angle of the crane cable when the pulley was moved without the crane boom rotating, which is the same as the equation of motion derived by Newton's method. It can be seen that.

As the equation of motion is calculated, the above equation may be summarized as follows.

Using the symbol V for the speed of the pulley and the angular velocity of the cable swing, the following equation can be simplified, which is suitable for the application of the Runge-Kutta method.

Hereinafter, a case in which only the boom is rotated will be described. In the case where the boom is rotated in the fixed state of the crane pulley, it appears as shown in FIG. 4. Figure 4 is a view showing the cable shake during the rotation of the boom in the crane applied to the present invention.

Referring to FIG. 4, the distance R from the vertical central axis of the crane to the pulley is constant, and the swing angle of the crane cable is the tangential swing angle α _T of the circle drawn by the boom rotation and the normal swing angle α perpendicular thereto. _It is divided by _R , and may be expressed by the rotation angle θ of the boom.

here,

Represented by

Through the consideration of the position and the speed as shown in Table 3 and Table 4, the following equation is established.

Pulley position and speed X ₁ = Rcosθ X ′ ₁ = -Rθ′sinθ Y ₁ = Rsinθ Y ′ ₁ = Rθ′cosθ Z ₁ = H Z ′ ₁ = 0

The position and velocity of the object X ₂ = (R + ξ) cosθ-ηsinθ X ′ ₂ = ξ′cosθ- (R + ξ) θ′sinθ-η′sinθ-ηθ′cosθ Y ₂ = (R + ξ) sinθ + ηcosθ Y ′ ₂ = ξ′sinθ + (R + ξ) θ′cosθ + η′cosθ-ηθ′sinθ Z ₂ = H + ζ Z ′ ₂ = ζ ′

In the above equations, the following equations may be derived from respective Lagrangian equations for general coordinates θ, ξ, η, ζ.

In order to apply the Runge-Kutta method, the equation of motion in the case of boom rotation is summarized as follows.

The angular velocity of the boom is ω, the tangential angular velocity of the cable is S _t , and the normal angular velocity of the cable is S _r .

As described above, the equations for the cable swing angle for the case of only the movement of the pulley and the case of the rotation of the boom have been completed.

On the other hand, consideration should be given to the case where the rotation of the boom and the pulley move simultaneously.

5 is a view of the cable shake during pulley movement and boom rotation in a crane applied to the present invention. As the boom rotates as shown in FIG. 5, the pulley becomes more complicated. To calculate the kinetic energy and potential energy, we first need to estimate the position and velocity equations. Formulas for position and velocity are shown in Tables 5 and 6.

Pulley position and speed X ₁ = Rcosθ X ′ ₁ = R′cosθ-Rθ′sinθ Y ₁ = Rsinθ Y ′ ₁ = R′sinθ + Rθ′cosθ Z ₁ = H Z ′ ₁ = 0

The position and velocity of the object X ₂ = (R + ξ) cosθ-ηsinθ X ′ ₂ = (R ′ + ξ ′) cosθ- (R + ξ) θ′sinθ-η′sinθ-ηθ′cosθ Y ₂ = (R + ξ) sinθ + ηcosθ Y ′ _{2 =} (R ′ + ξ ′) sinθ + (R + ξ) θ′cosθ + η′cosθ-ηθ′sinθ Z ₂ = H + ζ Z ′ ₂ = ζ ′

The equations for position and velocity in Tables 5 and 6 yield the following kinetic and potential energy equations.

In the above equation, the following equations can be derived from Lagrangian equations for general coordinates R, θ, ξ, η, ζ.

As described above, if Runge-Kutta method is applied to the equation of motion when the pulley moves and the boom rotates at the same time, the pulley moving speed (v), the boom rotational angular velocity (ω) and the tangential swing angular velocity of the cable ( s _t ), which can be simplified by the normal swing angular velocity (s _r ) symbol.

Once the kinematic equation of the crane cable is completed, it can be applied to the virtual reality simulation apparatus.

As a result of mathematical analysis of the above three cases, the control input of the crane is the pulley, that is, the acceleration of the crane. As the input of the acceleration profile as shown in FIG. 6, in which the crane tip is accelerated, moved, decelerated, and re-determined in a stationary state, a result can be obtained regarding the position of the pulley over time and the swing angle of the cable.

Here, the position of the pulley according to time {χ (t)} and velocity {ν (t)} by applying the above equations, which is the form of the cable's equation of motion, when the pulley moves with a time interval of 0.1 second by the Runge-Kutta method. , The cable swing angle {θ (t)} and the angular velocity {ω (t)}.

6 is a view showing an example of the acceleration profile for the pulley of the crane applied to the present invention. According to the acceleration input value shown in FIG. 6, the position of the pulley and the moving speed of the pulley are shown as the result shown in FIG. 7.

7 is a graph of the position and the speed of the pulley of the crane applied to the present invention. 8 is a graph of the swing angle and the angular velocity of the crane cable applied to the present invention.

Looking at Figure 7, it can be seen through the shape of the cable shakes as the pulley moves through FIG. While the pulley is accelerating, the cable starts to shake on the opposite side of the pulley progression, and the swing angle changes in the forward direction during the constant velocity movement. After the pulley stops, a certain amount of time must pass before the shaking of the cable disappears.

9 is a flowchart of a method for simulating the movement of a crane cable in accordance with the present invention.

First, since the motion equation to be applied is different for each dynamic movement of the tower crane, the physical model form of the crane is established in order to classify the movement by the same group (S10).

Since the present invention relates to a tower crane, it can be classified into a case in which only the pulley of the crane moves and a case in which the boom rotates and a case in which the boom rotates while the pulley moves.

If the model types are divided, the equations for the pulley and the position and velocity of the object should be considered first to derive the equations of motion for each of the divided types. Once the equations for position and velocity are derived, the equation of motion may be derived using the Lagrange equation (S12).

When the equation of motion is derived for each model, it is stored in the file (S14). Afterwards, the file can be loaded and read using a script (S16).

For example, the analysis result of the cable shake angle is stored in the 'CableAngle.txt' file and loaded from the 'CableAngle.script' indicating the cable shake.

Subsequently, the file is loaded using a script to visually connect the graphic object on the virtual reality simulation apparatus (applied to WorldUP) program to visualize the movement of the crane and the shaking of the cable according to the progress of the work (S18).

WorldUp (EAI-Sense8 Product) three-dimensional virtual reality application that is applied to the present invention has the advantage of providing a powerful real-time function in an object-oriented environment. In particular, it is an interpreter-based basic syntax scripting language that can be used in GUI development environment and can modify the behavior and characteristics of objects in real time rather than developing in compiled language.

Therefore, there is an advantage that it is easy to apply various changes, such as modifying the speed of the pulley during the simulation.

The scripts in the present invention are written so that the results of the pulley position and cable swing angle over time obtained through the motion analysis can be reflected in the visualization.

A script is a word that refers to a list of programs or commands that are translated or executed by another program. Popular ones include JavaScript, REXX, and Tcl / Tk. On the World Wide Web, scripting languages such as Perl and JavaScript are often used to provide input forms and other services.

In order to visualize the results of mathematical analysis such as the swing angle of crane cables and the position of pulleys, an object-oriented model for cranes and suspended objects must be devised.

In addition to the movement of the pulley along the crane's boom, a graphical model should be implemented to effectively represent the swinging of the cable that is affected by the boom's rotation and the pulley's movement. For example, when the boom rotates and the pulley moves, the cables and objects connected to the pulley are simultaneously rotated and moved, and there is shaking.

10 is a view for explaining the target of the motion graphics object for each part of the crane applied to the present invention. Referring to FIG. 10, the movement of graphic objects (Boom, Trolly, Cable, Object) is defined using a virtual reality simulation device (WorldUP) scripting language.

Using the position of the pulley obtained by the mathematical analysis process and the swing angle of the crane cable as input values to define the movement of the graphic object, a script is defined to define the position of the pulley over time and the swing of the crane cable.

The pseudo code in Table 7 is the part of the script where the stationary object is shaken by the angle CA1 around the z axis over the course of one second.

... T = SimulationTime set obj = Cable dim rot as orientation If T <= then obj.getrotation rot rot.z = 0, rot.y = 0, rot.x = 0 obj.setrotation rot End if If T> 0 and T <= 1 then obj.getrotation rot rot.x = 0, rot.y = 0, rot.z = CA1 obj.getrotation rot End if ...

In Table 7, T is the time of the system, and CA1 is called the shake angle at that time obtained through mathematical analysis. In the simulation of the crane cable, the swing angle of the cable is continuously updated in the above way.

11A to 11D are diagrams showing visually showing the propulsion of the crane cable in the virtual reality simulation apparatus according to the present invention as the time-based movement.

11A to 11D illustrate scenes in which each object (boom, pulley, cable) is shaken while the pulley moves because each position is changed by time by a script.

The drawings and detailed description of the invention are merely exemplary of the invention, which are used for the purpose of illustrating the invention only and are not intended to limit the scope of the invention as defined in the appended claims or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, the present invention is a physical model of the crane by distinguishing the motion equation and numerical analysis for the swing of the cable for the movement of the tower crane pulley and the rotation of the boom utilized in construction sites Presenting. By connecting the physical model with the graphic model, it is expected that the efficiency of construction graphic simulation can be improved, thereby securing the stability and constructability of the equipment operation of the construction site.

Claims (7)

In the motion analysis method of the construction graphic simulation system, Establishing a physical model form of a crane in order to classify the movements of the objects into the same group; In the step of establishing the model form, deriving a motion equation for each divided form; If the equations of motion are derived for each model, storing them in a corresponding file; Loading the file using a script; And A method of analyzing the movement of objects in a construction graphic simulation system comprising the step of visualizing the movement of an object as the work progresses by connecting to a graphic object on a virtual reality simulation device program. According to claim 1, In the step of establishing the physical model form of the crane in order to distinguish the movement of the object by the same group, A method for analyzing the motion of objects in a construction graphic simulation system, characterized in that the objects are moved independently by object, and the objects are moved together. The method of claim 1, wherein in the step of deriving a motion equation for each of the divided shapes, a motion equation is derived using a Lagrangian equation. 4. The method of claim 3, wherein the motion equations established by the Lagrangian method are numerically analyzed using the Runge Kutta method. The method of claim 1, wherein the storing in the corresponding file Method of motion analysis of objects in construction graphic simulation system characterized in that the result of motion analysis is saved as a text file. The exercise analysis result stored in the text file is A method for analyzing the movement of objects in a construction graphic simulation system, characterized in that the visualization is connected to graphic objects in a virtual reality program using a script. 7. The virtual reality program of claim 1 or 6, wherein the virtual reality program is A method for analyzing the motion of objects in a construction graphic simulation system, characterized in that the program supports an object-oriented environment for interaction between graphic objects.

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