Guidance system by control of derivative

• US 9,665,075 B2
• Filed: 05/04/2012
• Issued: 05/30/2017
• Est. Priority Date: 06/30/2011
• Status: Active Grant

• Current Assignee: Universidad Nacional de Educación a Distancia
• Original Assignee: Universidad Nacional de Educación a Distancia
• Inventors: Viudez Moreiras, Daniel, Nevado Reviriego, Antonio, Martin Sanchez, Juan Manuel
• Primary Examiner(s): Dunn, Darrin
• Application Number:
  US14/127,003
• Publication Number:
  US 20140207257A1
• Time in Patent Office: 1,852 Days
• CPC Class Codes: G05B 13/04 involving the use of models or simulators
• CPC Class Codes: G05B 13/048 using a predictor
• CPC Class Codes: G05D 1/00 Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots drive control systems specially adapted for autonomous road vehicles B60W60/00

Abstract

Guidance System for controlling output variables of single-input single-output or multi-input multi-output processes, where the process parameters are known or unknown and time-varying. The guidance system of the present invention generates a desired trajectory for a process output variable, and based on said desired trajectory, computes a set point for the derivative variable of said process output variable. This set point is then applied to a model based advanced controller for said derivative variable and the control action generated by said model based advanced controller is applied to the process and guides the process evolution in such a way that said process output variable converges towards said desired trajectory.

Claims

1. A method for generating a control vector during each of a plurality of control instants k, said control vector to be applied to an apparatus which carries out a process with at least one input variable and at least one output variable, at least one of said input variables defining a process input vector and at least one of said output variables defining a process output vector, said apparatus varying said process input vector in accordance with the value of said control vector u(k), said method guiding said process output vector v(k) towards an output set point vector, said method comprising the steps of:

(A) Generating a derivative vector {dot over (ν

)}(k) from said process output vector;

(B) Generating a future predetermined trajectory for driving said process output vector towards said output set point vector with a predetermined dynamic;

(C) Computing from said predetermined trajectory a derivative set point vector SP{dot over (ν

)}(k) for said derivative vector;

(D) Using an adaptive predictive controller for computing said control vector u(k), based upon components of the derivative vector and their corresponding derivative set points, that will drive said derivative vector {dot over (ν

)}(k) to said derivative set point vector SP{dot over (ν

)}(k) and, as a consequence, said output vector towards said predetermined trajectory, said adaptive predictive controller using an adaptive-predictive model to compute said control vector u(k) that will cause the predicted derivative vector to be at some value of said predetermined trajectory at a future time instant, being the parameters of said adaptive-predictive model updated on a real time basis in a manner which will cause said predicted derivative vector to approach the actual derivative vector;

(E) Applying said control vector u(k) to said apparatus in a manner which will cause said apparatus to vary said input vector in accordance therewith; and

(F) Actuating control of the process with said apparatus based on said at least one input variable.

2. The method of claim 1, wherein said method is characterized by controlling with a predetermined dynamic and simultaneously said process output vector ν

(k) and a derivative vector {dot over (ν

)}(k) of said process output vector.

3. The method of claim 1, wherein computing the future predetermined trajectory for each component of the output vector comprises taking into account the predetermined dynamics for said process and is performed as a function of both the output set point vector and the output vector.

4. The method of claim 3, wherein said predetermined trajectory for one of the components of said output vector is determined by an approaching increment towards a corresponding component of the output set point vector within a next updating period, when one of the said components of the output vector differs more than a certain distance from said corresponding component of the output set point vector, since said variable approaching increment is progressively reduced when one of the said components of the output vector approaches said corresponding component of the output set point vector within said certain distance.

5. A guidance system comprising a computer controller for generating a control vector during each of a plurality of control instants k, said control vector to be applied to an apparatus which carries out a process with at least one input variable and at least one output variable, at least one of said input variables defining an process input vector and at least one of said output variables defining a process output vector, said apparatus varying said process input vector in accordance with the value of said control vector u(k), said system guiding said process output vector ν

(k) towards an output set point vector SPν

(k), said computer controller being configured by a set of instructions to operate as;

a. a computation block responsive for generating a derivative vector V (k) from said process output vector ν

(k);

b. a guidance block responsive for;

(i) generating a future predetermined trajectory for driving said process output vector v(k) towards said output set point vector SPv(k) with a predetermined dynamic; and

(ii) computing from said future desired trajectory a derivative set point vector SP{dot over (ν

)}(k) for said derivative vector {dot over (ν

)}(k); and

c. an adaptive predictive controller for computing said control vector u(k), based upon components of the derivative vector and their corresponding derivative set points, that will drive said derivative vector {dot over (ν

)}(k) to said derivative set point vector SP{dot over (ν

)}(k) and, as a consequence, said process output vector towards said predetermined trajectory, said adaptive predictive controller using an adaptive-predictive model to compute said control vector u(k) that will cause the predicted derivative vector to be at some value of said predetermined trajectory at a future time instant, being the parameters of said adaptive-predictive model updated on a real time basis in a manner which will cause said predicted derivative vector to approach the actual derivative vector,

wherein said control vector u(k) is applied to said apparatus in a manner which will cause said apparatus to vary said input vector in accordance therewith, and wherein control of the process with said apparatus is actuated based on said at least one input variable.