Continuous circle gesture detection for a sensor system
A method for detecting a continuous circle gesture, has the following steps: receiving vectors representative of an object movement by a object detection unit; determining from the received sequence velocity vectors a sequence of velocity vectors or an approximation thereof; estimating an angle between subsequent velocity vectors; and determining a rotation direction.
1. A method for detecting a continuous circle gesture in a 2-dimensional touch positioning system, comprising
receiving a sequence of vectors representative of an object movement by an object detection unit, wherein the received sequence of vectors comprises measurement values m k (i) of electrodes i at times k;
determining from the received sequence of vectors a sequence of velocity vectors or an approximation thereof;
estimating an angle φ between subsequent velocity vectors; and
determining a rotation direction, wherein the rotation direction is determined by a sign of the estimated angle, wherein the angle φ between two subsequent velocity vectors v new and v old is approximately determined by φ≈sin φ≈ v new,x v old,y − v new,y v old,x .
2. The method according to claim 1 , wherein the received sequence of vectors are (x n ,y n ) position vectors of an object movement.
3. The method according to claim 2 , wherein velocity vectors are computed as the difference of subsequent position vectors.
4. The method according to claim 1 , wherein a circle counter is realized by integrating the angles between pairs of subsequent velocity vectors, or approximations of these angles.
5. The method according to claim 4 , wherein the circle counter is updated only if ∥v k ∥ exceeds a predetermined threshold.
6. The method according to claim 1 , wherein velocity vectors v new =v k and v old =v k-1 .
7. The method according to claim 1 , wherein the 2-dimensional touch positioning system is a track pad or a touch screen.
8. The method according to claim 7 , wherein the 2-dimensional touch positioning system is a capacitive near-field sensor system.
9. The method according to claim 8 , wherein the capacitive near-field sensor system comprises one or more transmission electrodes excited with a rectangular pulse train signal and a plurality of receiving electrodes capacitively coupled with the one or more transmission electrodes.
10. A method for detecting a continuous circle gesture in a 2-dimensional touch positioning system, comprising
receiving a sequence of vectors representative of an object movement by an object detection unit wherein the received sequence of vectors comprises measurement values m k (i) of electrodes i at times k;
determining from the received sequence of vectors a sequence of velocity vectors or an approximation thereof;
estimating an angle between subsequent velocity vectors; and
determining a rotation direction, wherein the rotation direction is determined by a sign of the estimated angle, wherein each velocity vector v new and v old in a sequence of two vectors is normalized by the same value ∥v new ∥ or ∥v old ∥.
11. The method according to claim 10 , wherein a circle counter is realized by integrating the angles between pairs of subsequent velocity vectors, or approximations of these angles.
12. The method according to claim 11 , wherein the circle counter is updated only if ∥v k ∥ exceeds a predetermined threshold.
13. The method according to claim 1 , wherein the received sequence and/or the velocity vectors and/or the circle counters are low-pass filtered.
14. A human device interface comprising:
a 2-dimensional touch positioning sensor device generating a sequence of vectors representative of an object movement tracked by a gesture detection system, wherein the received sequence of vectors comprises measurement values m k (i) of electrodes i at times k;
a processing unit configured
to determine from the received vectors a sequence of velocity vectors or an approximation thereof;
to estimate an angles φ between subsequent velocity vectors; and
to determine a rotation direction, wherein the rotation direction is determined by a sign of the estimated angle;
wherein the processing unit further implements a circle counter and updates values of the circle counter by adding the estimated angle with its sign depending on the rotating direction, wherein the angle φ between two subsequent velocity vectors v new and v old is approximately determined by φ≈sin φ= v new,x v old,y − v new,y v old,x .
15. The human device interface according to claim 14 , wherein the received sequence of vectors (x n ,y n ) represent position vectors of an object movement.
16. The human device interface according to claim 15 , wherein velocity vectors are computed as the difference of subsequent position vectors.
17. The human device interface according to claim 14 , wherein the angle between two subsequent velocity vectors
v
new
=
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x
v
new
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and
v
old
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is determined by φ=arc cos( v new T · v old )·S, where S∈{±1} is the rotating direction, T indicates the vector transpose, and the bar indicates normalization of a vector.
18. The human device interface according to claim 14 , wherein velocity v vectors v new =v k and v old =v k-1 .
19. The human device interface according to claim 14 , wherein a circle counter is realized by integrating the angles between pairs of subsequent velocity vectors, or approximations of these angles.
20. The human device interface according to claim 19 , wherein the circle counter is updated only if ∥v k ∥ exceeds a predetermined threshold.
21. The human device interface according to claim 19 , further comprising a first low-pass filter configured to filter the received sequence and/or a second low-pass filter configured to filter the velocity vectors and/or a third low-pass filter configured to filter the circle counter.
22. The human device interface according to claim 14 , wherein the 2-dimensional touch positioning sensor device is a track pad or a touch screen.
23. The human device interface according to claim 22 , wherein the 2-dimensional touch positioning sensor device is a capacitive near-field sensor system.
24. The human device interface according to claim 23 , wherein the capacitive near-field sensor system comprises one or more transmission electrodes excited with a rectangular pulse train signal and a plurality of receiving electrodes capacitively coupled with the one or more transmission electrodes.
25. An electronic device comprising a human device interface according to claim 14 , wherein the circle counter is used for volume control, a dimmer, speed control, air condition temperature, or mechanical movement functions.
26. The electronic device according to claim 25 , wherein the circle counter drives an LED bar.
27. A human device interface comprising:
a 2-dimensional touch positioning sensor device generating a sequence of vectors representative of an object movement tracked by a gesture detection system, wherein the received sequence of vectors comprises measurement values m k (i) of electrodes i at times k;
a processing unit configured
to determine from the received vectors a sequence of velocity vectors or an approximation thereof;
to estimate an angle between subsequent velocity vectors; and
to determine a rotation direction, wherein the rotation direction is determined by a sign of the estimated angle;
wherein the processing unit further implements a circle counter and updates values of the circle counter by adding the estimated angle with its sign depending on the rotating direction, wherein each velocity vector v new and v old in a sequence of two vectors is normalized by the same value ∥v new ∥ or ∥v old ∥.