Saturday, January 10, 2015

RJ11 Phone to RJ45 Jack

RJ11 Phone to RJ45 Jack - It used to be the case that budget phones were instantly recognisable by their low-resolution displays, meagre storage, and chunky, plastic bodies, but things are improving in this area all the time. These days, for £200 or less it's quite possible to buy a phone with a Full HD display and a sub 8mm-thick metal body. breaking the 9,000 barrier, well we have collected a lot of data from the field directly and from many other blogs so very complete his discussion here about RJ11 Phone to RJ45 Jack, on this blog we also have to provide the latest automotive information from all the brands associated with the automobile. ok please continue reading:

Kalman Filter (KF) 

Linear dynamical system (Linear RJ11 Phone to RJ45 Jack evolution functions)





Extended Kalman Filter (EKF) 

Non-linear dynamical system (Non-linear evolution functions)


Consider the following non-linear system:



Assume that we can somehow determine a reference trajectory 
Then:


where

For the measurement equation, we have:

We can then apply the standard Kalman filter to the linearized model
How to choose the reference trajectory?
Idea of the extended Kalman filter is to re-linearize the model around the most recent state estimate, i.e.



The Extended Kalman Filter (EKF) has become a standard    technique used in a number of 
# nonlinear estimation and 
# machine learning applications
#State estimation
#estimating the state of a nonlinear dynamic system
#Parameter estimation
#estimating parameters for nonlinear system identification
#e.g., learning the weights of a neural network
#dual estimation 
#both states and parameters are estimated simultaneously
#e.g., the Expectation Maximization (EM) algorithm

MATLAB CODE
########################################################################
function [x_next,P_next,x_dgr,P_dgr] = ekf(f,Q,h,y,R,del_f,del_h,x_hat,P_hat);
% Extended Kalman filter
%
% -------------------------------------------------------------------------
%
% State space model is
% X_k+1 = f_k(X_k) + V_k+1   -->  state update
% Y_k = h_k(X_k) + W_k       -->  measurement
%
% V_k+1 zero mean uncorrelated gaussian, cov(V_k) = Q_k
% W_k zero mean uncorrelated gaussian, cov(W_k) = R_k
% V_k & W_j are uncorrelated for every k,j
%
% -------------------------------------------------------------------------
%
% Inputs:
% f = f_k
% Q = Q_k+1
% h = h_k
% y = y_k
% R = R_k
% del_f = gradient of f_k
% del_h = gradient of h_k
% x_hat = current state prediction
% P_hat = current error covariance (predicted)
%
% -------------------------------------------------------------------------
%
% Outputs:
% x_next = next state prediction
% P_next = next error covariance (predicted)
% x_dgr = current state estimate
% P_dgr = current estimated error covariance
%
% -------------------------------------------------------------------------
%

if isa(f,'function_handle') & isa(h,'function_handle') & isa(del_f,'function_handle') & isa(del_h,'function_handle')
    y_hat = h(x_hat);
    y_tilde = y - y_hat;
    t = del_h(x_hat);
    tmp = P_hat*t;
    M = inv(t'*tmp+R+eps);
    K = tmp*M;
    p = del_f(x_hat);
    x_dgr = x_hat + K* y_tilde;
    x_next = f(x_dgr);
    P_dgr = P_hat - tmp*K';
    P_next = p* P_dgr* p' + Q;
else
    error('f, h, del_f, and del_h should be function handles')
    return
end

##############################################################################


For more

https://drive.google.com/folderview?id=0B2l8IvcdrC4oMzU3Z2NVXzQ0Y28&usp=sharing

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