Methods of developing a mathematical model of dynamics of a vehicle for use in a computer-controlled vehicle simulator

Patent metadata

Field	Value
Publication number	US-9760660-B2
Application number	US-201214009916-A
Country	US
Kind code	B2
Filing date	Oct 9, 2012
Priority date	Oct 6, 2011
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A method of developing a mathematical model of dynamics of a vehicle for use in a computer-controlled simulation, comprising: selecting a coefficient of a state-space model mathematically modelling the dynamics of the vehicle, the selected coefficient having a value for a predetermined state of the vehicle; and varying, a parameter of a physically-based computerized model mathematically modelling the dynamics of the vehicle, the parameter related to at least one of physical characteristics of the vehicle and phenomena influencing the dynamics of the vehicle, to improve the accuracy of the physically-based model via computer-implemented numerical optimization, the computer-implemented numerical optimization targeting the coefficient of the state-space model such that the difference between a value predicted by the physically-based model and the value of the coefficient of the state-space model for the predetermined vehicle state is within a predetermined range.

First claim

The invention claimed is:

1. A method of updating a dynamics model of a vehicle, the method comprising:
providing a state-space model having a plurality of coefficients describing the dynamics of the vehicle;
providing a physically-based model having a parameter related to a first predetermined vehicle state selected from a group consisting of (a) a set of physical characteristics of the vehicle, (b) a set of phenomena influencing the dynamics of the vehicle and (c) a combination thereof;
selecting a coefficient of the state-space model, the selected coefficient having a first value for the first predetermined state;
varying a value of the parameter of the physically-based model;
storing an updated value of the parameter of the physically-based model when a difference between a value predicted by the physically-based model and the value of the selected coefficient of the state-space model is within a first predetermined range for the first predetermined vehicle state; and
using the dynamics model of the vehicle in a computer-controlled vehicle simulation.

2. The method of claim 1 , comprising:
selecting a group of coefficients among the plurality of coefficients of the state-space model; and
storing the updated value of the parameter of the physically-based model when differences between values of each of the selected coefficients of the state-space model and values predicted by the physically-based model with respect to each corresponding selected coefficient are within the first predetermined range.

3. The method of claim 2 , wherein the selected group of coefficients defines a first group of coefficients, the method further comprising:
validating the updated physically-based model against actual vehicle operating data; and
if the validation fails:
changing at least one of the coefficients in the first group of coefficients to define a second group of coefficients, and
recalculating the differences from values predicted by the physically-based model based on the second group of coefficients.

4. The method of claim 1 , comprising concurrently varying a plurality of parameters of the physically-based model.

5. The method of claim 4 , comprising:
selecting a group of coefficients among the plurality of coefficients of the state-space model; and
storing updated values for each of the plurality of parameters of the physically-based model when differences between values of each of the selected coefficients of the state-space model and values predicted by the physically-based model with respect to each corresponding selected coefficient are within the first predetermined range.

6. The method of claim 4 , wherein the plurality of parameters defines a first plurality of parameters, the method further comprising:
validating the updated physically-based model against actual vehicle operating data; and
if the validation fails:
changing at least one of the parameters in the first plurality of parameters to define a second plurality of parameters, and
concurrently varying the second plurality of parameters.

7. The method of claim 1 , wherein the selected coefficient has a second value for a second predetermined vehicle state, the method comprising:
varying the value of the parameter of the physically-based model such that, concurrently:
a first difference between a first value predicted by the physically-based model and the first value of the coefficient of the state-space model for the first predetermined vehicle state is within the first predetermined range, and
a second difference between a second value predicted by the physically-based model and the second value of the coefficient of the state-space model for the second predetermined vehicle state is within a second predetermined range for the second predetermined vehicle state.

8. The method of claim 1 , comprising:
selecting a group of coefficients among the plurality of coefficients of the state-space model, each of the selected coefficients having a first value for the first predetermined vehicle state and a second value for a second predetermined vehicle state;
wherein, concurrently:
a first difference between the first value of each of the selected coefficients of the state-space model for the first predetermined vehicle state and a first value predicted by the physically-based model with respect to that coefficient is within the first predetermined range, and
a second difference between the second value of each of the selected coefficients of the state-space model for the second predetermined vehicle state and a second value predicted by the physically-based model with respect to that coefficient is within a second predetermined range for the second predetermined vehicle state.

9. The method of claim 1 , wherein the selected coefficient has a second value for a second predetermined vehicle state, the method comprising:
concurrently varying a plurality of parameters of the physically-based model such that, concurrently
a first difference between a first value predicted by the physically-based model and the first value of the coefficient of the state-space model for the first predetermined vehicle state is within the first predetermined range, and
a second difference between a second value predicted by the physically-based model and the second value of the coefficient of the state-space model for the second predetermined vehicle state is within a second predetermined range for the second predetermined vehicle state.

10. The method of claim 1 , comprising:
selecting a group of coefficients among the plurality of coefficients of the state-space model, each of the selected coefficients having a first value for the first predetermined vehicle state and a second value for a second predetermined vehicle state;
concurrently varying a plurality of parameters of the physically-based model such that, concurrently:
a first difference between the first value of each of the selected coefficients of the state-space model for the first predetermined vehicle state and a first value predicted by the physically-based model with respect to that coefficient is within the first predetermined range, and
a second difference between the second value of each of the selected coefficients of the state-space model for the second predetermined vehicle state and a second value predicted by the physically-based model with respect to that coefficient is within a second predetermined range for the second predetermined vehicle state.

11. The method of claim 1 , further comprising:
validating the updated physically-based model against actual vehicle operating data; and
if the validation fails:
altering at the first predetermined range; and
recalculating differences based on values predicted by the physically-based model.

12. The method of claim 1 , further comprising
validating the updated physically-based model against actual vehicle operating data; and
if the validation fails:
altering the physically-based model; and
recalculating differences based on values predicted by the altered physically-based model.

13. The method of claim 1 , wherein the physically-based model is constructed from a library of predetermined model components.

14. The method of claim 1 , wherein the coefficients of the state-space model are selected from a group consisting of stability and control derivatives of the state-space model.

15. The method of claim 1 , wherein the parameters of the physically-based model are selected from a group consisting of parameters related to rotor inflow, unsteady aerodynamics, fuselage aerodynamics, empennage aerodynamics, rotor

Assignees

• Cae Inc

Inventors

• Spira Daniel
• Myrand-Lapierre Vincent
• Soucy Olivier

Classifications

• G06F30/15

  Vehicle, aircraft or watercraft design · CPC title

• G09B23/02 Primary

  for mathematics (for statics or dynamics G09B23/08) · CPC title

• G06F2111/10

  Numerical modelling · CPC title

• G06Q10/04

  Forecasting or optimisation specially adapted for administrative or management purposes, e.g. linear programming or "cutting stock problem" (market predictions or forecasting for commercial activities G06Q30/0202) · CPC title

• G09B9/02

  for teaching control of vehicles or other craft · CPC title