Physics-based simulation of warhead and directed energy weapons

Abstract

A system and method are provided for distributed physics based simulation wherein a number of stations are connected via a network. When the simulation detects that a weapon, especially a missile or directed energy beam, is engaging a target vehicle, a single physics station is assigned the determination of the damage status of a target vehicle in the vicinity of the weapon. The detonation or strike of the weapon is applied to a model of the vehicle, wherein the vehicle is composed of pieces each made up of a number of parts, and damage is assessed. Where the damage to a piece of the vehicle exceeds a predetermined threshold, the piece is removed from the vehicle, and where a predetermined maximum damage is reached for the vehicle, the vehicle is destroyed in the simulation. The damage assessment from the weapon is made using raytracking component of a physics engine that is also used to control movement of virtual objects in the simulation according to rules of physics of the physics engine.

1 . A method for providing a computerized interactive simulation to a user at a simulation station communicating over a network, said method comprising:
 providing a computerized simulation of operation of the vehicle in a simulated environment using a first model of the vehicle that reflects operational characteristics of the vehicle being simulated;   providing a computerized simulation of a weapon operating in the simulated environment;   making a determination in said computerized simulation of an engagement of the weapon with the vehicle in the simulated environment;   responsive to the determination of the engagement of the weapon, performing a computerized interaction modeling of the weapon with an operational model of the vehicle;   determining as a result of said interaction modeling a damage model of the vehicle that differs from the operational model of the vehicle in that it reflects damage thereto defined by said interaction modeling; and   simulating movement and operation of said vehicle based on said damage model;   wherein the operational model of the vehicle comprises data defining a plurality of component pieces of the vehicle wherein each component piece has a respective maximum damage level, and the determination of the damage model includes the interactive modeling determining a damage level data value caused by the engagement of the weapon, said damage model reflecting destruction of any of the parts thereof where the damage data level exceeds the maximum damage level thereof.   
     
     
         2 . The method according to  claim 1 , wherein the computerized simulation of the vehicle includes
 storing physics data on a computer accessible memory coupled with a physics engine associated with the simulation station, said physics data defining physics parameters of a plurality of virtual objects in the simulated environment, and   determining movement of the vehicle in said simulated environment with said physics engine based on the physics data.   
     
     
         3 . The method according to  claim 2 , wherein the first model includes data defining is a first physics model of the vehicle, and the method further comprises determining movement of the vehicle in said simulated environment with said physics engine based on said data defining said first physics model of the vehicle. 
     
     
         4 . The method according to  claim 3 , wherein the vehicle is an aircraft and the simulation station includes a simulated aircraft cockpit and an image generating system generating out-the-window scene video in real time and displaying said video to said user using a display screen system. 
     
     
         5 . The method according to  claim 2 , wherein a simulation computer system transmits to the simulation station entity data identifying authoritative positions of virtual object entities in the simulation environment, and the simulation station applies forces in the physics engine toward synchronization of the virtual object entities toward the respective authoritative position. 
     
     
         6 . (canceled) 
     
     
         7 . The method according to  claim 1 , wherein, when a total of the damage level data values of all of the pieces exceeds a predetermined threshold, a determination of destruction of the vehicle is made and the simulation of the operation of the vehicle based on the damage model includes simulating the pieces of the vehicle all moving independently and unattached to each other. 
     
     
         8 . (canceled) 
     
     
         9 . The method according to  claim 1 , wherein the computerized simulation of the weapon is a simulation of a missile, and the computerized interaction modeling includes
 determining whether the missile detonates in simulation, and,   responsive to a determination that the missile has detonated,   applying a blast pressure computer model of blast pressure from the missile to the constituent parts of the vehicle that are exposed to the blast pressure so as to derive a data value of total blast force F experienced by each of said parts, wherein the total blast force F is determined according to the formula
     F=P*A*R   incidence    
   
       where P is the blast pressure at a point on the part, A is an area of the part, and R incidence  is a data value corresponding to a component based on an angle of incidence of the blast pressure on the part. 
     
     
         10 . The method according to  claim 1 , wherein the computerized simulation of the weapon is a simulation of a missile, and the computerized interaction modeling includes
 determining whether the missile detonates in simulation, and,   responsive to a determination that the missile has detonated,   calculating trajectories of fragments of the missile from a detonation model thereof, and   identifying by raycasting any of the parts of the vehicle model to which the fragment trajectories extend; and   determining for each of said parts a kinetic energy data value for the associated missile fragment based on a mass of the fragment specified in the missile detonation model and a velocity calculated for said fragment,   determining whether said kinetic energy data value exceeds a predetermined damage energy level.   
     
     
         11 . The method according to  claim 10 , wherein said raycasting is performed by the physics engine of the simulation station or another physics engine associated with another system on the network, said physics engine being assigned authoritative control of the vehicle for determining the position thereof while the determination of damage is being made. 
     
     
         12 . The method according to  claim 8  wherein the computerized simulation of the weapon is a simulation of a directed energy weapon, and the computerized interaction modeling includes determining a temperature of any part of the model that is exposed in the simulation to a directed energy beam hit the directed energy weapon, said temperature being determined using the physics engine of the simulation station or another physics engine by providing said physics engine with data corresponding to a mechanical analogue of the directed energy beam hit. 
     
     
         13 . The method according to  claim 12  wherein and further comprising determining destruction of said part if the temperature exceeds a predetermined maximum temperature. 
     
     
         14 . The method according to  claim 12 , wherein the temperature is based on a recorded series of simulated directed energy beam hits, and the modeling includes modeling heating of the part during each of the beam hits and cooling of the part after each of the beam hits. 
     
     
         15 . A system for distributed simulation of aircraft in combat, said system comprising:
 a plurality of simulation stations for respective users connected via a network, each of simulation stations having a respective physics engine and data storage storing scene data defining a version of a shared simulation environment containing virtual entities, including a respective aircraft associated with each simulation station, and in which positions of the virtual entities are determined by the physics engine applying physics rules;   said simulation stations each including a display visible to the user and an image generator rendering from the scene data a sequence of frames of out-the-window video displayed thereon in real time;   a simulation administration computer system storing data corresponding to authoritative positions of entities in the simulation environment; and   a physics station connected with the network and comprising a physics engine;   the simulation administration computer system transmitting physics data units of said authoritative states for said entities over the network to the simulation stations;   said simulation stations each receiving said physics data units and deriving force data values therefrom that are applied to the respective physics engine so as to cause the entities in the respective scene data to each move toward the respective authoritative state according to the physics rules;   said simulation administration computer system administering simulation of one or more weapon systems, and, when the weapon system is fired, said simulation system determining if there is a weapon system engagement with any of the aircraft, and, responsive to a determination of an engagement, the simulation administration computer system executes a handoff of control of the authoritative position of said aircraft to the physics station, such that the physics station determines the authoritative position of the aircraft for the system;   said physics system accessing data defining a target model of the aircraft responsive to said handoff and performing a weapon interaction modeling of the engagement;   
       said target model data including data defining a plurality of pieces of the aircraft that are fixedly connected with each other in the simulation, each piece having a respective maximum damage value, and each piece being composed of a plurality of subsidiary parts connected together in the model, said parts each being a primitive planar facet of a wireframe of the aircraft model;
 said physics station performing the weapon interaction modeling using a ray-casting or ray-tracing function of the physics engine thereof so as to identify parts subject to damage, and determining for each piece a total damage of all parts thereof and a damage level data value indicative of a degree of damage experienced by the piece; 
 said physics station determining from comparison of all of the damage level data values for all of the pieces with the respective maximum damage values of the pieces, aircraft damage data indicating that the aircraft is either undamaged, destroyed or partially damaged, and if partially damaged, identifying the pieces that are damaged; 
 said physics system transmitting said aircraft damage data to said simulation administration computer system, wherein the aircraft damage data is used to modify the authoritative state data of the aircraft if the aircraft is destroyed or partially damaged; and 
 wherein if the aircraft is partially damaged, the simulation continues with the aircraft simulation without the part or parts that were determined to be damaged. 
 
     
     
         16 . (canceled) 
     
     
         17 . The system according to  claim 15 , wherein the system supports a visualization module that modifies data in the system that displays the aircraft such that damage levels of parts of the aircraft are shown in corresponding colors. 
     
     
         18 . The system according to  claim 15 , wherein said simulated weapon system is of a missile, and the physics station determines responsive to firing thereof whether the missile detonates, said weapon interaction modeling for the missile includes a blast damage determination and a fragmentation damage determination. 
     
     
         19 . The system according to  claim 18  wherein the blast damage determination comprises applying a blast pressure computer model of blast pressure from the missile to the parts of the vehicle that are exposed to the blast pressure so as to derive a data value of total blast force F experienced by each of said parts, the total blast force F being determined according to the formula
     F=P*A*R   incidence    
 
       where P is the blast pressure at a point on the part, A is an area of the part, and R incidence  is a data value corresponding to the ratio of a component normal to the plane relative to the direction of an angle of incidence of the blast pressure on the part; and
 wherein the fragmentation damage determination comprises: 
 calculating trajectories of fragments of the missile from a detonation model thereof, and 
 identifying by raycasting any of the parts of the target model to which the fragment trajectories extend; and 
 determining for each of said parts a kinetic energy data value for the associated missile fragment based on a mass of the fragment specified in the missile detonation model and a velocity calculated for said fragment, 
 determining whether said kinetic energy data value exceeds a predetermined damage energy level. 
 
     
     
         20 . The system according to  claim 15 , wherein the weapon system simulated is a directed energy weapon, and wherein the weapon interaction modeling includes determining a temperature of any part of the model that is exposed in the simulation to a directed energy beam hit from the directed energy weapon, said determining of temperature including thermal modeling heating and cooling of the part during a period of time starting with firing of the directed energy weapon, the thermal modeling using the physics engine of the simulation station or another physics engine to calculate the temperature of the part by providing said physics engine with data corresponding to a mechanical analogue of the directed energy beam hit, and determining destruction of said part if the temperature exceeds a predetermined maximum temperature. 
     
     
         21 . The system according to  claim 20 , wherein the mechanical analogue is a physics-based model of a box of specified weight being pushed by a specified force on a surface having a specified friction, wherein the specified force is defined by a value determined as a heat flux of the directed beam hit in the simulation. 
     
     
         22 . The system according to  claim 15 , wherein one of the simulations stations determines authoritative position data of the associated simulated aircraft defined as a first aircraft model and transmits said authoritative position data to the said simulation administration computer system, which stores said authoritative position data as the authoritative position of the aircraft in the simulation;
 wherein, when there is a weapon system engagement with said aircraft, the physics system determines authoritative target data defining the authoritative position of the aircraft using data defining a target model of the aircraft and sends authoritative target data therefrom to said simulation administration computer system, which stores said authoritative position data as the authoritative position of the aircraft in the simulation; and   wherein, when the aircraft damage data is sent to the said simulation administration computer system, said simulation station returns to determining the authoritative position of the aircraft with a model adjusted according to the aircraft damage data.   
     
     
         23 . A method of operating a physics-based simulation system for simulating a vehicle and a weapon system, said system having first and second computerized stations connect via a network, each of said stations including a respective physics engine, said method comprising the steps of:
 modeling at the first computerized station operation of the vehicle using a vehicle model and transmitting entity state data for said vehicle over the network as a master synchronizer therefor;   modeling at the second computerized station operation of the weapons system using a weapon model and transmitting authoritative entity state data for said weapons system over the network as a master synchronizer therefor;   responsive to a determination of firing of the weapon, assigning one of the computerized stations or a third computerized station having a respective physics engine as master synchronizer for both the vehicle and the weapon;   modeling using the physics engine at said assigned computerized station engagement of the weapon with the vehicle using a damage assessment model of the vehicle so as to produce damage assessment data; and   modeling at the first computerized station subsequent operation of the vehicle using the vehicle model or a version thereof reflecting damage defined by the damage assessment data; and   wherein the damage assessment model is of a vehicle made up of parts each having a respective damage limit, and the damage assessment data is based on a comparison for each part of damage thereto from the weapon with said damage limit, and   wherein the vehicle model used for the modeling of the subsequent operation of the vehicle reflects the damage by a modification of the data defining arts that have been damaged according to the damage assessment data.   
     
     
         24 . The method according to  claim 23 , wherein the vehicle is an aircraft. 
     
     
         25 . (canceled) 
     
     
         26 . The method according to  claim 23  wherein the model of the weapon corresponds to a missile, and includes data defining parts of the missile that become fragments each following a respective trajectory after a detonation, said modeling including a making determination using ray casting of the physics engine and the parts of the damage assessment model struck by said fragments travelling along said trajectories. 
     
     
         27 . The method according to  claim 26 , wherein the fragment trajectories in simulation are straight lines. 
     
     
         28 . The method according to  claim 25 , wherein the weapon is modeled as a directed energy weapon, and an effect of a beam hit by the directed energy weapon on one or more of the parts of the damage assessment model is determined using the physics engine to model heating and cooling of the part or parts using a mechanical analogue model that emulates the effect of the beam. 
     
     
         29 . The method according to  claim 23 , wherein the damage status report data includes data indicating that the vehicle is partly damaged, and the assigned computerized station continues to control the vehicle as a master synchronizer therefor using data received from the first computer system, which is a simulator station accommodating a human user controlling the vehicle.