Method and device for real-time differentiation of analog and digital signals

Patent metadata

Field	Value
Publication number	US-9910411-B2
Application number	US-201113979603-A
Country	US
Kind code	B2
Filing date	Jan 14, 2011
Priority date	Jan 14, 2011
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

The controller includes a differentiating engine configured to receive an input signal value (ISV), wherein the ISV corresponds to state information for one selected from a group consisting of a controlled process and a user interface. The differentiating engine is further configured to determine an error between the ISV and an estimated input signal (EIS), estimate a frequency of the IS, select a plurality of pre-determined gains using the frequency, wherein at least one plurality of pre-determined gains is a suction control gain, determine a first estimated derivative of the input signal (EDIS) using the plurality of pre-determined gains and the error, and to output the first EDIS.

First claim

What is claimed is:

1. A non-transitory computer readable medium comprising instructions, which when executed by a processor performs a method, the method comprising:
obtaining, by a virtual system dynamics controller, an input signal value (ISV) from an input signal (IS), wherein the ISV corresponds to state information for a user interface of a haptic interface device, wherein the haptic interface device is associated with a virtual system;
determining, by the virtual system dynamics controller, an error between the ISV and an estimated input signal (EIS);
obtaining, by the virtual system dynamics controller, a plurality of pre-determined gains, wherein the plurality of pre-determined gains are obtained using

d
dt

⁡

[

α
⁡

(
t
)

λ
⁡

(
t
)

]

=

-

Γ
⁡

[

v
⁡

(
t
)



e
⁡

(
t
)



1
/
2

⁢

sign
⁡

(

e
⁡

(
t
)

)

]

⁢

(

C
-



e
⁡

(
t
)



)

,

where α(t) is a first differentiator gain and λ(t) is a second differentiator gain of the plurality of pre-determined gains, where e(t) is the error between the ISV and the EIS, where Γ is a positive definite matrix, where v(t) is an intermediate variable, and where C is an adaptive offset constant;
wherein the virtual system dynamics controller is further configured to estimate a frequency of the IS, wherein the plurality of pre-determined gains are obtained using the frequency, and wherein the plurality of pre-determined gains are obtained from a lookup table comprising optimal gains for each of a plurality of input signal frequencies;
determining, by the virtual system dynamics controller, a first estimated derivative of the input signal (EDIS) using the plurality of pre-determined gains and the error, comprising: using u(t)=v(t)−λ|e(t)| 1/2 sat(ke)(t)), wherein λ is a differentiator gain and k is a suction control gain of the plurality of pre-determined gains, where e(t) is the error between the ISV and the EIS, and where v(t) is an intermediate variable;
simulating, by the virtual system dynamics controller, dynamics of the virtual system based at least on the first EDIS to obtain simulation data;
generating, by the virtual system dynamics controller, a control signal using the simulation data, wherein the control signal is used to create a haptic feedback signal used to control a state of the haptic interface device;
outputting, by the virtual system dynamics controller, the control signal to the haptic interface device;
and
outputting, by the virtual system dynamics controller, at least the simulation data to a virtual system display associated with the virtual system.

2. The non-transitory computer readable medium of claim 1 , wherein the method further comprises: determining, by the virtual system dynamics controller, a derivative of an intermediate variable (DIV) using v′(t)=−αsat(ke(t)), wherein α is a differentiator gain and k is a suction control gain of the plurality of pre-determined gains, and where e(t) is the error between the ISV and the EIS;
determining, by the virtual system dynamics controller, a second value of an intermediate variable (IV) using DIV and a first value of the IV;
determining, by the virtual system dynamics controller, a second EIS using the first EDIS and the EIS;
obtaining, by the virtual system dynamics controller, a second ISV from the IS; estimating, by the virtual system dynamics controller, a second frequency of the IS;
selecting, by the virtual system dynamics controller, a second plurality of pre-determined gains using the second frequency; determining, by the virtual system dynamics controller, a second error between the second ISV and second EIS;
determining, by the virtual system dynamics controller, a second EDIS using the second plurality of pre-determined gains and the second error;
and
outputting, by the virtual system dynamics controller, the second EDIS.

Assignees

• Celik Ozkan
• Chawda Vinay
• Omalley Marcia K
• Univ Rice William M

Inventors

• Celik Ozkan
• Chawda Vinay
• Omalley Marcia K

Classifications

• G06F3/016

  Input arrangements with force or tactile feedback as computer generated output to the user · CPC title

• G05B13/02 Primary

  electric · CPC title

• G06F3/05

  Digital input using the sampling of an analogue quantity at regular intervals of time {, input from a/d converter or output to d/a converter} · CPC title

• G06F3/011 Primary

  Arrangements for interaction with the human body, e.g. for user immersion in virtual reality (blind teaching G09B21/00) · CPC title

• G05B15/02

  electric · CPC title