JP2021077149A - Information processing method, information processing equipment, and robot system - Google Patents

Abstract

To obtain proximity points required for contact force calculation according to the analytical method so that appropriate and highly accurate simulation processing can be continued, even after an overlap occurs.SOLUTION: When multiple object models overlap in a certain simulation step (S8), the state of simulation is rolled back to a second simulation step in the past where no overlap has occurred (S10). In the rolled-back simulation step, proximity points that are close to each other within a predetermined threshold of the object models are acquired (S11 to S14), and relative velocities before and after the contact of the acquired proximity points are used to calculate a contact force acting between the object models when the object models come into contact with each other (S16).SELECTED DRAWING: Figure 3

Description

The present invention relates to an information processing method, an information processing device, and a robot system that perform a simulation of operating at least one object model in a virtual space in which a plurality of object models exist.

Recently, robots are used in various production sites, and the demand for simulators that can check the operation of these robots offline is increasing. For example, dynamics that support assembly process design by simulating whether a robot collides with other jigs or by simulating the behavior of parts that make up a mechanism such as a robot, jig, or work with a computer. Simulation can be mentioned.

When performing a dynamics simulation of the process of assembling an object with an industrial robot, it is necessary to accurately calculate the contact force generated when the object models come into contact with each other. This contact force calculation method can be roughly divided into a penalty method with a small amount of calculation and an analysis method with a large amount of calculation but whose accuracy is theoretically guaranteed.

Patent Document 1 discloses a method for solving a problem when elastic calculation is introduced into a penalty method for obtaining a contact force from an amount of overlap between object models. In the method of Patent Document 1, the calculation time is subdivided in order to reduce the calculation error that occurs at the start and end of the contact.

Non-Patent Document 1 discloses a method for accurately calculating a contact force by using an analysis method. In the method of Non-Patent Document 1, simultaneous equations are established so that the relative velocities before and after contact are theoretically correct at the proximity points between objects, and linear complementation is performed using conditional equations regarding the velocity and contact force of the proximity points. It is solved as a sexual problem.

Japanese Unexamined Patent Publication No. 2011-123558

“Fast Contact Force Computation for Non-Penetrating Rigid Bodies”, SIGGRAPH 94, pp. 23-34 (1994).

In fields such as computer graphics, the penalty method tends to be used to calculate contact force. On the other hand, in the simulation of industrial robots, the analysis method is desirable because the calculation of contact force requires accuracy.

In the analysis method, the proximity points when the objects are sufficiently close to each other are used to calculate the contact force, but when the objects overlap each other, the proximity points cannot be calculated. Therefore, before the overlap, it is necessary to determine whether or not the objects are sufficiently close to each other by comparing the distance between the objects with the contact threshold value. At this time, a relatively large contact threshold value is set for the purpose of preventing the overlapping state of the objects. As a result, a point far from the actual contact point tends to be selected as a proximity point for force calculation, which may reduce the simulation accuracy.

In view of the above problems, the object of the present invention is to obtain the proximity points required for the contact force calculation of the analysis method even after the overlap occurs, and to continue the appropriate and highly accurate simulation processing. To do.

In order to solve the above problems, in the present invention, in an information processing method for performing a simulation in which at least one object model is operated in a virtual space where a plurality of object models exist, a control device is used in a first simulation step. It is determined whether or not the overlap of the plurality of object models has occurred, and if the overlap of the plurality of object models has occurred, the simulation state is the second simulation step in the past in which the overlap does not occur. In the step of rolling back to and the second simulation step of rolling back, the control device acquires proximity points that are close to each other within a predetermined threshold of the object model, and the acquired proximity points of the acquired proximity points. A configuration including a step of calculating the contact force acting between the object models when the object models come into contact with each other by using the relative velocities before and after the contact is adopted.

According to the above configuration, even after the overlap of the object models occurs, the proximity points required for the contact force calculation of the analysis method can be obtained, and the appropriate and highly accurate simulation processing can be continued.

It is a block diagram which showed the control system of the simulation apparatus as the information processing apparatus which concerns on embodiment of this invention. It is a flowchart which showed the outline of the simulation process which concerns on embodiment of this invention. It is a flowchart which showed the calculation process of the simulation which concerns on embodiment of this invention in detail. (A) to (d) are explanatory views showing various states relating to overlap between object models. It is explanatory drawing which showed the example of the expansion of the contact threshold value which concerns on embodiment of this invention. It is explanatory drawing which showed the structural example of the user interface which sets the contact threshold value which concerns on embodiment of this invention. It is explanatory drawing which showed the appearance of the simulation apparatus which concerns on embodiment of this invention, and the structural example of the screen display. It is explanatory drawing which showed the configuration example of the user interface for setting the robot control program which concerns on embodiment of this invention. It is explanatory drawing which showed the structural example of the user interface used when the maximum number of rollbacks is exceeded in embodiment of this invention. It is explanatory drawing which showed the structural example of the user interface used when the contact threshold value exceeds the maximum value in embodiment of this invention. It is a flowchart which showed in detail the calculation process of the simulation which considered the initial value of the contact threshold value which concerns on embodiment of this invention. It is explanatory drawing which showed the structural example of the user interface which can set the initial value of the contact threshold value which concerns on embodiment of this invention. It is explanatory drawing which showed the velocity when the object models come into contact with each other. It is explanatory drawing which showed the relative velocity between object models. In the embodiment of the present invention, it is explanatory drawing which showed the determination which concerns on the distance, contact state, or overlap between objects using the contact threshold value.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. The configuration shown below is merely an example, and for example, a person skilled in the art can appropriately change the detailed configuration without departing from the spirit of the present invention. Moreover, the numerical values taken up in this embodiment are merely examples of reference numerical values.

<Embodiment 1>
FIG. 1 shows a configuration example of an information processing apparatus capable of executing the simulation process (information processing method) of the present embodiment. The device of FIG. 1 is, for example, a simulation device for operating an object model corresponding to an object to be operated by the robot device in a virtual space in a mode described in a robot control program for controlling the robot device.

The simulation device 1 of FIG. 1 includes a CPU 20 as a calculation unit, a ROM 21, a RAM 22, an HDD 23 as a storage medium, a recording disk drive 24, and various interfaces 25, 26, 27, 28. The ROM 21, RAM 22, HDD 23, recording disk drive 24, and interfaces 25, 26, 27, and 28 are connected to the CPU 20 so as to be able to communicate with each other via the bus 29.

Further, FIG. 7 shows an example of a configuration including the simulation device 1, a robot control device 180, and a robot system including the robot device 181. In FIG. 7, the simulation device 1 is illustrated as a control terminal in the form of, for example, a PC (personal computer) including blocks (ROM21, RAM22, HDD23, etc.) centered on the CPU 20 of FIG. A keyboard 11, a mouse 12, and a monitor 13 are connected to the simulation device 1.

The monitor 13 of FIG. 7 displays the simulation screen 100. The simulation screen 100 includes a CG screen that displays a robot model and parts (object models) operated by the robot model. The simulation screen 100 further includes a user interface 40 (FIG. 6) for performing setting operations such as a contact threshold value, a user interface 1000 (FIG. 8) for setting a robot control program, and the like.

The simulation device 1 of the present embodiment is intended to be used for offline confirmation of the operation of the robot device 181 accompanied by contact. For example, in FIG. 7, the simulation device 1 can be used for verification of a robot control program for the robot control device 180 to drive and control the robot device 181. For example, the validity of the robot control program that drives and controls the robot device 181 can be verified by simulating the movement of each object such as the hand 182, the arm, and the workpieces 183 and 184 to be operated with contact.

Various programs for operating the CPU 20 are stored in the ROM 21, and the CPU 20 can execute arithmetic processing of a component assembly simulation described later based on the programs stored in the ROM 21. The RAM 22 is a storage means for temporarily storing the processing result of the CPU 20. The HDD 23 is a storage device, and stores various information such as component data, dynamics calculation, and contact force calculation formulas in advance. Further, the CPU 20 stores data such as a calculation result by the CPU 20 in the HDD 23.

The control system of FIG. 1 is composed of a CPU 20 as a main control means, a ROM 21 as a storage device, and PC hardware including a RAM 22. The ROM 21 can store a control program of the CPU 20, constant information, and the like for realizing the assembly simulation of the present embodiment. Further, the RAM 22 is used as a work area of the CPU 20 when executing the control procedure.

The control program of the CPU 20 for realizing the simulation process of the present embodiment can be stored in a storage unit such as the above-mentioned HDD 23 or ROM 21 (for example, EEPROM area). In that case, the control program of the CPU 20 for realizing the control procedure of the present embodiment can be supplied to each of the above-mentioned storage units via a network interface or the like, and can be updated to a new (other) program. Alternatively, the control program of the CPU 20 for realizing the control procedure described later can be supplied from, for example, the recording disk drive 24 to each of the above-mentioned storage units, and the contents thereof can be updated. The recording disk drive 24 includes, for example, storage means such as various magnetic disks, optical disks, and flash memories, and a drive device for the storage means. Various storage means, storage units, or storage devices in a state in which the control program of the CPU 20 for realizing the control procedure of the present embodiment is stored constitutes a computer-readable recording medium in which the control procedure of the present invention is stored. It will be.

The simulation device 1 includes an operation input unit including a keyboard 11 connected via the interface 25 and a mouse 12 connected via the interface 26. The user can perform various setting operations through the user interface configured by using the operation input unit hardware. Further, the simulation device 1 is provided with a monitor 13 connected via an interface 27, and can display various screens such as a data input (editing) screen and a display screen for displaying parts and the like in a virtual three-dimensional space. It has become. Further, the interface 28 is configured so that an external storage device 14 such as a rewritable non-volatile memory or an external HDD can be connected.

FIG. 2 shows the processing flow of the entire simulation. The simulation process described below operates at least one object model in a virtual space in which a plurality of object models exist. The object model as these simulation models is, for example, an industrial robot device, an object such as a work corresponding to the robot device, or an obstacle placed in a real environment (corresponding to a virtual space) in which the robot device is placed. Corresponds to an object such as an object. The object model in the following virtual space may be simply described as "object". In addition, in the following explanation of simulation processing, object models corresponding to objects such as parts (work) robots (devices) and obstacles are also referred to as "parts (work)", "robots (devices)", "obstacles", etc. , May be referred to by the member name in the actual environment.

In the present embodiment, for example, in the embodiment described in the robot control program that controls the robot device that operates the robot device, the object model corresponding to the target object operated by the robot device is operated in the virtual space. By this simulation process, the robot operation described in the robot control program can be verified. Then, using a robot control program that has been verified or further modified as necessary, an assembly operation that causes an actual robot device to operate a work corresponding to an object model can be performed, and for example, an article can be manufactured. ..

The simulation process of this embodiment is performed as follows. First, read the information such as the link and work position information of the robot device, mass, moment of inertia, center of gravity position, the object model described as a 3D model, its initial displacement, initial velocity, initial acceleration, etc., and set the simulation model. Do (S1).

Next, simulation conditions related to the entire simulation, such as a simulation time, a simulation time interval, a coefficient of restitution between objects, and a predetermined threshold value for determining that parts are in contact with each other, that is, a contact threshold value, are set (S2). When the simulation is ready to be performed, the simulation calculation is started (S3).

In the simulation calculation of this embodiment, the calculation is performed step by step to proceed with the simulation. Here, the simulation calculation of the present embodiment will be described with reference to FIGS. 3 and 4.

FIG. 3 shows a flowchart of simulation calculation including contact calculation. In the simulation calculation, first, the position and speed in the current simulation step (first simulation step) are backed up for use after rolling back to the past simulation step described later (S4). The variable area of the position and acceleration indicated by _{q backup} in the following equation is secured in, for example, RAM 22.

Next, for the rollback described later, the number of proximity points used in the contact calculation of the simulation is cleared to zero (S5). The outline of this contact calculation is, for example, a determination process as shown in the following pseudo program code.

Next, the dynamics calculation as shown in the following equation is performed, and the acceleration is calculated from the force applied to the object (S6). In that case, the equation of motion of the rigid body can be described as shown in the following equation.

In the above equation, q, its derivative, and the second derivative are the displacement, velocity, and acceleration of the rigid body, respectively, and τ is the contact force applied to the rigid body. Further, H () is an inertial term, C () is a Coriolis / centrifugal term, and G () is a gravity term. Using the contact force τ in the above equation, the acceleration can be calculated from the contact force applied to the rigid body as in the equation below.

Next, an integral calculation is performed to calculate the velocity and position from the acceleration (S7). The initial state of a rigid body is generally given by the following equation.

In the simulation calculation, the next state (simulation step) advanced by the discrete step (t) from this initial state (initial simulation step) is continuously calculated by the numerical integration method. For example, in the case of Euler integration, the simulation calculation can be calculated as follows.

Then, in the simulation step after this step, contact calculation is performed to confirm whether or not there is overlap between the parts (S8). If there is no overlap here (NO in S8), it is confirmed whether the simulation is completed (S9), and if the simulation is continued (NO in S9), the control is looped and the calculation of the next simulation step is started. ..

4 (a) to 4 (d) show an example of the simulation calculation result. In FIGS. 4A to 4D, the object 31 is an object to be simulated, and the objects 331 and 332 show obstacles. Here, the object 31 and the objects 331 and 332 approach each other at different velocities. Suppose you have. By performing the simulation calculation, the object 31 to be simulated moves to the position shown in 32, 327 to 329 in FIGS. 4 (a) to 4 (d). In the case of 32 and 329, the object and the obstacle do not overlap.

By the way, since the simulation calculation is performed in discrete steps, for example, as shown in FIGS. 4A to 4D, when the positions are calculated, the objects, for example, the objects 331 to 332 and the objects 327 to 328 overlap each other. there's a possibility that.

When calculating the contact force by the analysis method, it is necessary to calculate the proximity points between the objects, but if the overlap occurs, the proximity points cannot be calculated, so the contact force cannot be calculated. FIG. 4B shows the result of the simulation calculation when they overlap. Here, as a result of the simulation calculation, as shown by 327, the object 31 overlaps with the object 331 (obstacle). Then, when the overlap is confirmed (YES in S8), the simulation state is rolled back to the past simulation step (S10). In this rollback operation, the backed up simulation data (position, acceleration variable region shown in Equation 1) is used to return the simulation state (position, acceleration) to the previous state (simulation step) as shown in the following equation.

As shown in FIG. 4B, when the overlap of the objects is detected in the discrete step t + Δt, it is treated as if the contact force was generated in the step rolled back as described above (second simulation step). Specifically, the contact threshold is expanded until the object is within the contact threshold (S11 in FIG. 3), and whether or not the object is within the contact threshold is determined (S12), and then the proximity point. Acquisition calculation (S13) is performed. At the end of the contact threshold expansion flow, it is determined whether or not the number of proximity points has increased due to the threshold expansion (S14), and if the number of proximity points has increased (YES in S14), the number of proximity points is saved (S15). ). This storage of the number of proximity points is performed because it is necessary when the overlap determination occurs again based on the contact force calculation after the contact threshold value is expanded.

It should be noted that known techniques can be used for overlapping objects (for example, parts and workpieces operated by a robot) and a method for determining whether objects exist within a contact threshold value. Techniques for this type of interference detection are described, for example, in "Real-Time Collection Detection", CRC Press, 2004 and the like.

For example, the contact confirmation of parts is performed using the triangular polygon information of the 3D model. By determining whether or not each of the elements of the triangular polygons of the two parts intersects, it is possible to confirm whether or not the objects are in contact with each other. There are various methods for determining the presence or absence of intersections between triangles, but it can be easily calculated by geometric calculation using the relationship of the information of the three vertices of a triangle. Similarly, whether or not the objects exist within the contact threshold value is determined by comparing the distance L and the threshold value T for each of the triangular polygons of the two parts in the calculation as shown in the pseudo program code below. It can be easily determined.

If the object is within the contact threshold, the contact force is calculated (S16). This contact force is calculated by using the method described in Non-Patent Document 1. In this method of Non-Patent Document 1, simultaneous equations are established so that the relative velocities before and after contact are theoretically correct at the proximity points between objects, and linear equations are used for the velocity and contact force of the proximity points. It is solved as a complementarity problem.

FIG. 5 shows a data manipulation that expands the contact threshold for the object 31 and the object 33. In the present embodiment, the contact threshold value is a standard for assuming that contact occurs when objects are closer to each other than this value. In FIG. 5, the contact threshold value is initially 351 and at this time, the object 31 and the object 33 (obstacle) do not exist within the distance within the threshold value (351). In the process of this embodiment, in this case, the contact threshold is expanded to the state of 352. At this time, since the object 31 and the obstacle 33 exist at a relative distance of the contact threshold value, they can be treated as if they are in contact with each other. Regarding this threshold value expansion operation, it is conceivable that the expansion amount at the time of rollback is set in advance in the simulation condition setting (S2).

FIG. 8 shows a user interface 1000 for setting a robot control program. The user interface 1000 of FIG. 8 can be operated by clicking or dragging the mouse 12, or operating a keyboard shortcut from the keyboard 11. The dialog of the user interface 1000 has a menu 101, which is implemented in the form of, for example, a pull-down (up) menu, and is configured so that a robot control program to be used for simulation can be specified. The menu item of the menu 101 lists the robot control programs currently stored in the HDD 23 or the like.

When the robot control program is selected from the menu 101 and the start button 1011 of FIG. 8 is operated, the simulation of operating the virtual robot can be started so as to perform the operation defined by the robot control program in the virtual space. The operation of the virtual robot (which is, of course, also one of the object models to be simulated) can be animated and displayed in the simulation screen 100 of FIG. 7, for example, in a form such as 3D display. The stop button 1012 of FIG. 8 is used to stop (pause) the started simulation.

In the robot control program selected by the user interface 1000 of FIG. 8, parameters such as position control and force control are described. In the virtual environment to be simulated, of course, parts such as the arm and hand of the robot device are treated as an object model together with the work operated by the robot device. By operating these object models according to the robot control program in the simulation environment, for example, the validity of the robot control program can be verified.

Since the contact calculation in the simulation calculation has a high calculation cost, it is preferable to be able to adjust the accuracy and speed of the simulation by using the interface 40 as shown in FIG.

In the dialog of the user interface 40 of FIG. 6, the field 43 is, for example, a numerical input field for specifying the maximum number of rollbacks. The user can specify an upper limit of the number of rollbacks performed in S10 of FIG. 3 via the field 43. The value of the maximum number of rollbacks is an effective setting item for eliminating the possibility of an infinite loop of the flow starting from S10.

When the maximum number of rollbacks reaches the upper limit value specified via the field 43, the dialog 1100 as shown in FIG. 9 is popped up and the user is asked whether to continue the simulation. The dialog 1100 of FIG. 9 includes a message 1103 that notifies that the maximum number of rollbacks has reached a specified upper limit value, for example, by displaying a symbol such as a text or an icon. Further, the dialog 1100 of FIG. 9 has a continuation button 1101 for the user to continue the simulation and a stop button 1102 for stopping the simulation.

In the dialog constituting the user interface 40 of FIG. 6, the field 44 is, for example, a numerical input field for the user to specify the expansion width of the contact threshold value. The expansion width of the contact threshold value corresponds to the expansion width of the contact threshold value used in S11 of FIG. The smaller the enlargement width given here, the higher the accuracy of the contact calculation, but the higher the calculation cost. In the field 44, it is not possible to set an enlargement width of 0 or less.

In the dialog 40 of FIG. 6, the field 45 is, for example, a numerical input field for the user to specify the maximum value of the contact threshold value used in S11 to S13 of FIG. This maximum value of the contact threshold is effective in eliminating the possibility of an infinite loop of the flow starting from S10 in FIG.

When the contact threshold value specified from the field 45 of FIG. 6 reaches the upper limit (maximum value), a dialog as shown in FIG. 10 is presented. It is appropriate to ask the user how to continue the simulation. Further, the dialog 1100 of FIG. 10 includes a message 1104 that notifies that the contact threshold has reached the upper limit (maximum value), for example, by displaying a symbol such as a text or an icon. Further, the dialog 1100 of FIG. 10 has a continuation button 1101 for the user to continue the simulation and a stop button 1102 for stopping the simulation.

FIG. 4C shows an example of the simulation result when the simulation of FIG. 4B is rolled back, the threshold value is expanded, and the proximity point is calculated. 341 and 342 in FIG. 4 represent close points between objects 31 and 332. The proximity point 341 and the proximity point 342 are paired, and the directions of the repulsive force and the frictional force are calculated based on the positional relationship between the two points. In the example of FIG. 4 (c), as a result of performing simulation calculation based on the contact force with respect to the object 31 shown by the solid line, as shown in 328, the object 31 to be simulated overlaps with the obstacle 331. The result is that.

FIG. 4D shows a state in which the simulation step is rolled back and the proximity points 341 and 342 of the object 31 and 332 and the proximity points 343 and 344 of the object 31 and 331 are calculated. From this state, the contact force can be simulated and calculated from the position, velocity, acceleration, and the like of the object 31.

As a result, the overlap between the object 31 and the obstacle 33, which invalidates the contact force calculation, is eliminated. Then, in this case, the simulation in which the object 31 calculated from the rollback position, speed, acceleration, etc. of the simulation bounces off due to the contact force with respect to the object 331 and the object 332 can be executed (329).

As described above, according to the simulation calculation of the present embodiment, the simulation calculation can be appropriately continued even when the objects overlap with each other during the simulation. Further, according to the user interface of the present embodiment, when the simulation is rolled back, the contact threshold value can be increased, thereby increasing the possibility of eliminating the overlap from the rolled back state. Can be done. Further, according to the user interface of the present embodiment, the expansion width of the contact threshold value can be limited to a small value, and the simulation can be continued from a position closer to the contact state where the objects are closer to each other. This can improve the accuracy of the contact force calculation of the continuing simulation. Further, if the overlap is not eliminated even after the rollback is performed, the overlap can be repeated and executed. In that case, according to the user interface of the present embodiment, the number of repeated executions can be limited, and it is possible to avoid an obstacle such that the simulation calculation enters an infinite loop state.

That is, according to the present embodiment, in the simulation process using the contact force between a plurality of objects, the simulation using the analysis method can be continued even if the objects overlap each other. Further, when the overlap occurs, the minimum contact threshold value is determined according to the situation. Therefore, unlike the prior art, it is not necessary to set a large contact threshold value in advance, and the accuracy of contact simulation is improved. In addition, the calculation can proceed so that the contact force is calculated only when the objects overlap each other, and the determination within the contact threshold between the objects while the objects do not overlap can be omitted, so that the processing cost is increased. It can be reduced.

<Embodiment 2>
Before the start of the simulation, the initial value of the above-mentioned contact threshold value is appropriately set, and the control procedure is configured so that the simulation calculation of the contact force is performed without rolling back before the overlap between the object models occurs. You can also do it.

In the control procedure of FIG. 11 of the present embodiment, step S17 for determining the initial value of the contact threshold value and branching to step S13 when the object models are close to each other within the contact threshold value is added to the control of FIG. It is a thing. Since the other steps in FIG. 11 are the same as those described in FIG. 3 above, duplicate description will be omitted here.

Further, FIG. 12 shows a user interface in which an input field 46 for setting an initial value of the contact threshold value is added to the user interface of FIG. 6 in consideration of the initial value of the contact threshold value. In the user interface of FIG. 12, the initial value of the contact threshold value set by the input field 46 is the initial value of the contact threshold value used in step S17 of FIG.

As described above, the present embodiment is configured so that the branch of step S17 is added to the simulation control as shown in FIG. 11 and the initial value of the contact threshold value can be appropriately set. With such a configuration, it is possible to perform the simulation calculation of the contact force without performing rollback before the overlap between the object models occurs. Therefore, according to the present embodiment, the contact force simulation can be made faster.

The simulation device is configured so that both the control procedure of FIG. 3 and the control procedure of FIG. 11 are prepared so that either control procedure can be selected via an appropriate selection user interface (not shown). You may. Alternatively, the selected user interface may be configured by a radio button or the like that determines whether or not to insert (enable) the branch control in step S17 of FIG. With such a configuration, it is possible to select to use the control of FIG. 3 in the simulation where the contact state is expected to be small, and to use the control of FIG. 11 in the simulation where the contact state is expected to be large. Become.

<Embodiment 3>
In the first embodiment, when overlap occurs during simulation and rollback is performed, the contact threshold value for determining the overlap or proximity state between the object models can be expanded, and the expansion width can be set. The configuration is illustrated.

In the example of the first embodiment, the expansion width of the contact threshold value is manually set. However, according to such a manual setting, an unfavorable control state may occur due to an inconsistency between the setting of the expansion width of the contact threshold selected by the user and the configuration of the environment or model to be simulated. For example, if the expansion width of the contact threshold value is too small, the number of times the threshold value expansion is repeated until the proximity point is detected increases, and if it is too large, an unintended proximity point is detected.

Therefore, a configuration is conceivable in which the appropriate value of the expansion width of the contact threshold value is automatically set according to the state of the object model. In this embodiment, an example of calculating and setting the expansion width of the contact threshold value based on the state of the object model, for example, the relative velocity of the object model is shown.

FIG. 13 shows object models 36, 39 (eg, parts) that overlap during simulation. Here, the object model 36 has a velocity 38 such that it moves to the position 37 after one step, and the object model 39 has a velocity 41 that moves to the position 42 after one step. According to the same control as in the first embodiment, when the object models 36 and 39 occupy the positions 37 and 42, the overlap occurs and the simulation step is rolled back.

In this case, in the present embodiment, the expansion width of the contact threshold value is calculated by an operation such as the following equation. _{First, the relative velocity 42-1 (v rel} ) of the object model 36 and the object model 39 is calculated by using the velocity 38 (v ₁ ) of the object model 36 and the velocity 41 (v _{2) of the object model 39.} Here, FIG. 14 is a vector representation of _{the velocity 38 (v 1} ) in FIG. 13, the velocity 41 (v ₂ ) of the object model 39, and the relative velocity 42-1 (v _{rel) of the object model 36 and the object model 39.} Shown.

Then, by multiplying the relative velocity by the time (Δt) of one step of the simulation as shown in the following equation, the distance (D) that each object model (for example, a part) approaches in one step of the simulation can be calculated.

As described above, by multiplying the relative velocity 42-1 by the time of one step of the simulation as the expansion width of the contact threshold value, the proximity point 43-1 between the objects can be obtained by at most one trial of the contact threshold expansion. And a pair of proximity points 43-2 can be obtained (Fig. 15).

As described above, according to the present embodiment, it is possible to automatically set an appropriate value of the expansion width of the contact threshold value of the object model required for the simulation process according to the state of the object model. For example, the expansion width of the contact threshold value can be calculated and set based on the state of the object model, for example, the relative velocity of the object model. Therefore, it is not necessary to perform manual setting that requires skill, and it is possible to automatically set an appropriate value of the expansion width of the contact threshold value of the object model required for the simulation process according to the state of the object model.

The present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or device via a network or storage medium, and one or more processors in the computer of the system or device reads and executes the program. But it is feasible. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

1 ... Simulation device, 13 ... Monitor, 20 ... CPU, 21 ... ROM, 22 ... RAM, 23 ... HDD, 25-28 ... Interface, 1000 ... User interface, 1011 ... Start button, 1012 ... Stop button, 31, 32, 331, 332 ... Object (object model).

Claims (16)

In an information processing method that simulates the operation of at least one object model in a virtual space where multiple object models exist.
In the first simulation step, the control device determines whether or not the overlap of the plurality of object models has occurred, and if the overlap of the plurality of object models has occurred, the simulation states are overlapped. The process of rolling back to the second simulation step in the past where
In the second simulation step rolled back, the control device acquires proximity points that are close to each other within a predetermined threshold of the object model, and the acquired proximity points are relative to each other before and after contact. An information processing method including a step of calculating a contact force acting between the object models when the object models come into contact with each other using a speed. In the information processing method according to claim 1, when the control device acquires the proximity point in the second simulation step rolled back, the threshold value is set from an initial value so that the proximity point can be obtained. An information processing method for acquiring proximity points that are close to each other within a predetermined threshold value of the object model. In the information processing method according to claim 1, the control device repeatedly tries to acquire the proximity points while expanding the threshold value, and when the number of proximity points between the object models increases, the acquired said. An information processing method for calculating the contact force between the object models using the relative velocities before and after the contact of the proximity points. The information processing method according to claim 2 or 3, wherein the control device receives an operation of setting a numerical value related to the threshold value by a user via a user interface device. The information processing method according to any one of claims 2 to 4, wherein the control device determines the expansion width of the threshold value by using the relative speed between the object models. In the information processing method according to any one of claims 1 to 5, the control device causes overlap of a plurality of object models depending on the presence or absence of intersection of polygons constituting the plurality of object models. An information processing method that determines whether or not a polygon is used. A control program for causing a computer constituting the control device to execute each step according to the information processing method according to any one of claims 1 to 6. A computer-readable recording medium in which the control program according to claim 7 is stored. In an information processing device that performs simulation to operate at least one object model in a virtual space where a plurality of object models exist.
In the first simulation step, it is determined whether or not the overlap of the plurality of object models has occurred, and if the overlap of the plurality of object models has occurred, the simulation states have not overlapped. In the second simulation step of rolling back to the second simulation step in the past and rolling back, the proximity points close to each other within a predetermined threshold of the object model are acquired, and the acquired proximity points of the acquired proximity points are acquired. An information processing device including a control device that calculates the contact force acting between the object models when the object models come into contact with each other by using the relative velocities before and after the contact. In the information processing device according to claim 9, when the control device acquires the proximity point in the second simulation step rolled back, the threshold value is expanded from the initial value to obtain the object model. An information processing device that acquires proximity points that are close to each other within a predetermined threshold. In the information processing device according to claim 9, the control device repeatedly tries to acquire the proximity points while expanding the threshold value, and acquires the proximity points when the number of proximity points between the object models increases. An information processing device that calculates the contact force between the object models using the relative velocities before and after the contact of the proximity points. In the information processing device according to claim 10 or 11, the information processing device receives an operation of setting a numerical value related to the threshold value by a user via a user interface device. The information processing device according to any one of claims 10 to 12, wherein the control device determines the expansion width of the threshold value by using the relative speed between the object models. In the information processing device according to any one of claims 9 to 13, the control device causes the plurality of object models to overlap depending on the presence or absence of intersection of polygons constituting the plurality of object models. An information processing device that determines whether or not it has occurred. The robot device includes the information processing device according to any one of claims 9 to 14 and a robot device, and the robot device is described in a robot control program for controlling the robot device. A robot system in which the robot control program is verified by operating the object model corresponding to the target object operated by the robot in the virtual space, and the robot device is operated by the verified robot control program. A method for manufacturing an article in which a work as a target object is operated by the robot device of the robot system according to claim 15 and an article is manufactured from the work.

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