Reply by gorlic February 10, 20052005-02-10
>Using 'n' for time, to denote sampling: > >x(n+1) = A x(n) + B_i U(n) + B_n W(n) >y(n) = C_m x(n) + D_i U(n) + D_n W(n) > >A = 1, B_i = 0, B_n = 0, C_m = 1, D_i = cos(theta(n)), D_n = >cos(theta(n)), x(0) = C. > >This is saved from being a no-state model (A, B_i and B_n empty) by the >constant error. Otherwise you don't have any states, so it's a little >silly modeling it with state-space. >
>Tim Wescott >Wescott Design Services >http://www.wescottdesign.com >
First of all, thanks for help! But I still have some questions: 1) To my knowledge, I think c_m = cos(theta(n)), so that it can go back to the sensor relation function. 2) Why you say that A (=1) is empty? 3) y(n) is not in the form of measurement model: z(k)= H(k)x(k)+ v(k). How to deal with U(n) when a kalman filter is used to estimate the state of the sensor? Thanks! This message was sent using the Comp.DSP web interface on www.DSPRelated.com
Reply by Tim Wescott February 7, 20052005-02-07
gorlic wrote:

> Tim Wescott wrote: > >> ... >> >> >>>What are you really trying to do, and why do you want to model > > stateless > >>>systems with state-space representations? >> > I want to use the kalman filter to detect the sensor fault. Any better > way? > > Thanks! > > > > This message was sent using the Comp.DSP web interface on DSPRelated.com
If you have a model of the expected sensor output in azimuth and you expect the sensor to behave in a markedly different way when it is broken then a kalman filter of some sort may be part of the solution -- your kalman filter structure would then have more to do with the vehicle dynamics than the (nonexistent) sensor dynamics. Have fun -- BIT has always struck me as a good way to generate false alarms. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com
Reply by gorlic February 5, 20052005-02-05
Tim Wescott wrote:
> > ... > >> What are you really trying to do, and why do you want to model
stateless
>> systems with state-space representations? >
I want to use the kalman filter to detect the sensor fault. Any better way? Thanks! This message was sent using the Comp.DSP web interface on DSPRelated.com
Reply by Jerry Avins February 4, 20052005-02-04
Tim Wescott wrote:

  ...

> What are you really trying to do, and why do you want to model stateless > systems with state-space representations?
Homework, probably. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by Tim Wescott February 4, 20052005-02-04
gorlic wrote:
> In my sensor implementation, I got a function: > > Y(t)=cos(theta(t))*( U(t) + W(t)+ C ) > > Where t denotes the sampling time, Y denotes the measured azimuth, > 'theta' denotes the angle of the hilly road, U denotes the real > azimuth(input), W denotes the zero mean Gaussian white noise, C denotes > calibration error(constant). > > How to transfer this relation function to the state space model? > > Thanks! > > > This message was sent using the Comp.DSP web interface on DSPRelated.com
Using 'n' for time, to denote sampling: x(n+1) = A x(n) + B_i U(n) + B_n W(n) y(n) = C_m x(n) + D_i U(n) + D_n W(n) A = 1, B_i = 0, B_n = 0, C_m = 1, D_i = cos(theta(n)), D_n = cos(theta(n)), x(0) = C. This is saved from being a no-state model (A, B_i and B_n empty) by the constant error. Otherwise you don't have any states, so it's a little silly modeling it with state-space. What are you really trying to do, and why do you want to model stateless systems with state-space representations? -- Tim Wescott Wescott Design Services http://www.wescottdesign.com
Reply by gorlic February 4, 20052005-02-04
In my sensor implementation, I got a function:

Y(t)=cos(theta(t))*( U(t) + W(t)+ C )

Where t  denotes the sampling time, Y denotes the measured azimuth,
'theta'  denotes the angle of the hilly road, U denotes the real
azimuth(input), W denotes the zero mean Gaussian white noise, C denotes
calibration error(constant).

How to transfer this relation function to the state space model?

Thanks!

		
		This message was sent using the Comp.DSP web interface on DSPRelated.com