US 8,803,822 B2Granted

Time-reversal-based impact-localization and haptic-feedback method for touch panels

AssigneeNational Chiao Tung University

InventorsMingsian R. Bai, Yao Kun Tsai

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Abstract

The present invention provides a time-reversal-based impact-localization and haptic-feedback method for touch panels. Firstly, a plate model for an elastic plate and the impulse responses thereof are constructed according a plate theory. Next, a mathematical model is established according to the impulse responses and a time-reversal approach. When an impact force hits the elastic plate, the touched point on the elastic plate generates a touch signal, and the touch signal is received by at least a sensor at the corner of the elastic plate. The touch signal is converted into a time-reversal signal according to the mathematical model by a simulator. The time-reversal signal is reversed to the touched point for simulating reversal vibration waves of the time-reversal signal on the elastic plate, and locating the touched point.

A time-reversal-based impact-localization and haptic-feedback method for touch panels, comprising steps:

constructing a plate model of an elastic plate according a plate theory, wherein said plate model is constructed according to a plurality of material parameters of said elastic plate, including thickness, unit impulse density and bending stiffness, Young's modulus, and a Poisson ratio of said elastic plate;
calculating an impulse response di(t) of an arbitrary point i of said elastic plate in accordance with:
d
i
⁡
(
t
)
=
∑
i
=
1
L
⁢
⁢
w
il
⁡
(
x
,
y
,
t
)
⊗
r
l
⁡
(
t
)
,
wherein {circle around (x)} is the linear time convolution, i is the number of the touchable points on the elastic plate, ri(t) is the force applied to the elastic plate, wherein l=1, 2, . . . , L, wherein L is the number of a sensor, and wil(x,y,t) is the transfersal displacement of said arbitrary point i described by said plate model di(t);
using a time-reversal approach to construct a mathematic model according to said impulse response;
using at least one sensor at a corner of said elastic plate to receive a touch signal generated via applying an external force to a touched point of said elastic plate;
and
using a simulator to convert said touch signal into as thine-reversal signal according to said time-reversal approach and retransmit said time-reversal signal emitted by said at least one sensor to said touched point to simulate a waveform of backward-propagation vibration and position said touched point, wherein said feedback-induced vibration is simulated in accordance with
w
il
⁡
(
x
,
y
,
t
)
=
∑
m
=
1
∞
⁢
⁢
∑
n
=
1
∞
⁢
⁢
4
Ω
mn
⁢
abh
⁢
⁢
ρ
⁢
sin
⁢
m
⁢
⁢
π
⁢
⁢
x
i
a
⁢
sin
⁢
n
⁢
⁢
π
⁢
⁢
y
i
b
⁢
sin
⁢
m
⁢
⁢
π
⁢
⁢
x
l
a
⁢
sin
⁢
n
⁢
⁢
π
⁢
⁢
y
l
b
⁢
sin
⁡
(
Ω
mn
⁢
t
)
.
wherein ρ is the density of the elastic plate, w is the transversal displacement, h is the thickness of the elastic plate, (x0, y0) is the touched point, and wherein D is the bending stiffness per unit length expressed by
D
=
Eh
3
12
⁢
(
1
-
υ
2
)
,
wherein E and ν are the Young's modulus and Poisson ratio of the elastic plate, respectively, and wherein
Ω
mn
=
D
ρ
⁢
⁢
h
[
(
m
⁢
⁢
π
a
)
2
+
(
n
⁢
⁢
π
b
)
2
]
,
wherein a and b are the length and width of the elastic plate, respectively.

171 more elements

Facts

Application

13/030,322Filed 18 Feb 2011

Priority

TW 99138516 A9 Nov 2010

Published

US 2012/0113020 A110 May 2012

Granted

12 Aug 2014

Term ends

Not estimatedThe source records don’t support an estimate.

Classification3 codes

G06F 3/016
Input arrangements or combined input and output arrangements for interaction between user and computer: input arrangements with force or tactile…
G06F 3/043
Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means: using propagating acoustic waves
G06F
Computing and data processing

Abstract

Claims8