Method and system for qualitative reasoning of spatio-temporal physical systems

Patent metadata

Field	Value
Publication number	US-11860682-B2
Application number	US-201916724983-A
Country	US
Kind code	B2
Filing date	Dec 23, 2019
Priority date	Dec 23, 2019
Publication date	Jan 2, 2024
Grant date	Jan 2, 2024

Abstract

The techniques discussed herein generally relate to a method and system for qualitative modeling of and reasoning about the behavior of spatio-temporal physical systems. In some embodiments, qualitative representations based on Tonti diagrams are used to describe lumped or distributed parameter systems. Using a topological structure of the physical system, some embodiments generate qualitative governing equations as symbolic constraints on qualitative state variables. The qualitative constraints may be used to produce a qualitative simulation of the physical system. The qualitative simulation may be used to guide conceptual design iterations with given design criteria, or for instantiation of quantitative or hybrid (qualitative and quantitative) models and simulations.

First claim

What is claimed is:

1. A device comprising:
at least one processor;
and at least one memory including computer program code;
the at least one memory and the computer program code configured to, with the at least one processor, cause the device to:
specify a topological structure of a physical system in space-time;
construct a qualitative spatio-temporal model of the physical system, wherein the qualitative spatio-temporal model of the physical system is expressed by topological semantics based on a Tonti diagram in which qualitative states of physical variable are systematically organized as nodes on the Tonti diagram and governing expressions constraining the qualitative states are symbolically expressed as connections between selected nodes on the Tonti diagram; and
using both the topological structure and the qualitative spatio-temporal model, simulate the qualitative spatio-temporal behaviors of the physical system as a discrete set of state transitions in space-time to produce a simulation of the physical system.

2. The device according to claim 1 , wherein the device is further caused to perform spatio-temporal multi-physics qualitative reasoning.

3. The device according to claim 1 , wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the device to produce the simulation using a qualitative reasoning tool.

4. The device according to claim 1 , wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the device to:
specify at least one design criteria; and
test the results of simulation against the design criteria.

5. The device according to claim 1 , wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the device to use the simulation of the physical system to modify the qualitative spatio-temporal model of the physical system.

6. The device according to claim 1 , wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the device to perform the following operations:
(i) specify at least one design criteria;
(ii) update at least one qualitative parameter of a set of qualitative parameters of the simulation of the physical system; and
(iii) iterate though operation (ii) until the results of the simulation of the physical system satisfy the design criteria.

7. The device according to claim 1 , wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the device to:
using fully or partially provided quantitative information of the qualitative spatio-temporal model of the physical system, instantiate the qualitative spatio-temporal model of the physical system into a quantitative or hybrid (qualitative and quantitative) model; and
simulate the quantitative or hybrid model using one of qualitative, quantitative, or hybrid computational tools.

8. A device for generating qualitative constraints that govern a spatio-temporal behavior of a physical system, the device comprising:
at least one processor;
and at least one memory including computer program code;
the at least one memory and the computer program code configured to, with the at least one processor, cause the device to:
specify a topological structure of the physical system in space-time; and
using the topological structure, generate the qualitative constraints in symbolic form, wherein the qualitative constraints may be fed into a qualitative simulation tool comprising a qualitative spatio-temporal model wherein the qualitative spatio-temporal model of the physical system is expressed by topological semantics based on a Tonti diagram in which qualitative states of physical variable are systematically organized as nodes on the Tonti diagram and governing expressions constraining the qualitative states are symbolically expressed as connections between selected nodes on the Tonti diagram.

9. The device of claim 8 , wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the device to generate the qualitative constraints based on at least one of defining, topological, constitutive, and interaction equations.

10. The device of claim 8 , wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the device to feed the qualitative constraints into the qualitative simulation tool to produce a simulation of the physical system.

11. The device of claim 8 , wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the device to:
feed the qualitative constraints into the qualitative simulation tool to produce a simulation of the physical system; and
use the simulation of the physical system to modify the qualitative model of the physical system.

12. The device according to claim 8 , wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the device to perform the following operations:
(i) specify at least one design criteria;
(ii) update at least one qualitive parameter of a set of qualitative parameters of the simulation of the physical system by; and
(iii) iterate though operation (ii) until the results of the simulation of the physical system satisfy the design criteria.

13. The device of claim 8 , wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the device to:
use the generated qualitative constraints to produce the qualitative model of the physical system; and
using fully or partially provided quantitative information of the physical system, instantiate the qualitative model into a quantitative or hybrid (qualitative and quantitative) model.

14. The device of claim 8 , wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the device to:
use the generated qualitative constraints to produce the qualitative model of the physical system;
using fully or partially provided quantitative information of the physical system, instantiate the qualitative model into a quantitative or hybrid (qualitative and quantitative) model; and
simulate the quantitative or hybrid model using one of qualitative, quantitative, or hybrid computational tools.

15. A method for qualitatively simulating spatio-temporal behaviors of a physical system, said method comprising:
specifying a topological structure of the physical system in space-time;
constructing a qualitative spatio-temporal model of the physical system, wherein the qualitative spatio-temporal model of the physical system is expressed by topological semantics based on a Tonti diagram in which qualitative states of physical variable are systematically organized as nodes on the Tonti diagram and governing expressions constraining the qualitative states are symbolically expressed as connections between selected nodes on the Tonti diagram; and
using both the topological structure and the qualitative spatio-temporal model in conjunction with performing spatio-temporal multi-physics qualitative reasoning to simulate the qualitative spatio-temporal behaviors of the physical system as a discrete set of state transitions in space-time.

16. A device comprising:
at least one processor;
and at least one

Assignees

• Palo Alto Res Ct Inc
• Xerox Corp

Inventors

• Behandish Morad
• De Kleer Johan
• Wang Randi

Classifications

• G06F30/20 Primary

  Design optimisation, verification or simulation (optimisation, verification or simulation of circuit designs G06F30/30) · CPC title

• G06N5/04

  Inference or reasoning models · CPC title

• G06F30/23

  using finite element methods [FEM] or finite difference methods [FDM] · CPC title

• G06F2111/04

  Constraint-based CAD · CPC title

• G06N5/01

  Dynamic search techniques; Heuristics; Dynamic trees; Branch-and-bound · CPC title