Retinal-inspired method and system for improved detection
View Patent ↗The present disclosure provides a method and device for filtering sensor data. Signals from an array of sensor pixels are received and checked for changes in pixel values. Motion is detected based on the changes in pixel values, and motion output signals are transmitted to a processing station. If the sum of correlated changes in pixel values across a predetermined field of view exceeds a predetermined value, indicating sensor jitter, the motion output signals are suppressed. If a sum of motion values within a defined subsection of the field of view exceeds a predetermined threshold, indicating the presence of a large object of no interest, the motion output signals are suppressed for that subsection.
1. A sensor data preprocessing device, comprising:
a first layer of detectors configured to receive signals from an array of sensor pixels and determine changes in pixel values;
a second layer of detectors configured to receive the changes in pixel values from the first layer, detect motion based on the changes in pixel values and transmit motion value output signals to a processing station;
a third layer of detectors configured to receive the changes in pixel values from the first layer and detect global motion of objects represented by correlated changes in pixel values across a predetermined field of view, wherein the third layer is configured to produce a first suppressive signal that is applied to the motion value output signals of the second layer of detectors only if a sum of correlated changes in pixel values within the predetermined field of view exceeds a predetermined threshold; and
a fourth layer of detectors configured to receive motion output signals from the second layer and detect large environmental objects by integrating motion values within defined subsections of the predetermined field of view, wherein the fourth layer is configured to produce a second suppressive signal that is applied to the motion value output signals of detectors in the second layer for a subsection only if a sum of motion values within that subsection exceeds a predetermined threshold.
2. The device according to claim 1 , wherein the device is incorporated into a remote sensor.
3. The device according to claim 2 , wherein the remote sensor is selected from among the following:
a camera;
an unmanned aerial vehicle (UAV);
telescope;
satellite.
4. The device according to claim 1 , wherein the first layer is configured to transmit only positive changes in pixel values to the second layer.
5. The device according to claim 1 , wherein the first layer is configured to transmit only negative changes in pixel values to the second layer.
6. The device according to claim 1 , wherein the first layer is configured to transmit both positive and negative changes in pixel values to the second layer.
7. The device according to claim 1 , wherein the second layer is configured to detect motion across two pixels.
8. The device according to claim 1 , wherein the sum of correlated changes in pixel values across the field of view exceeding the predetermined threshold indicates sensor jitter.
9. The device according to claim 1 , wherein the sum of motion values within a subsection exceeding the predetermined threshold indicates the presence of an object larger than a predetermined size to be considered of interest.
10. The device according to claim 1 , wherein subsections of the field of view are defined by predetermined distances between sensor pixels.
11. The device according to claim 1 , wherein the device is implemented at least in part in neuromorphic hardware.
12. The device according to claim 1 , wherein the device is implemented at least in part in a field programmable gate array (FPGA).
13. A method of preprocessing sensor data, comprising the steps of:
receiving, by a first layer of detectors, signals from an array of sensor pixels;
determining, by the first layer of detectors, changes in pixel values;
detecting, by a second layer of detectors, motion based on the changes in pixel values;
transmitting, by the second layer of detectors, motion value output signals to a processing station;
detecting, by a third layer of detectors, global motion of objects represented by correlated changes in pixel values across a predetermined field of view;
producing, by the third layer of detectors, a first suppressive signal that is applied to the motion value output signals of the second layer of detectors only if a sum of correlated changes in pixel values within the predetermined field of view exceeds a predetermined threshold;
detecting, by a fourth layer of detectors, large environmental objects by integrating motion values within defined subsections of the predetermined field of view; and
producing, by the fourth layer of detectors, a second suppressive signal that is applied to the motion value output signals of detectors in the second layer for a subsection only if a sum of motion values within that subsection exceeds a predetermined threshold.
14. The method according to claim 13 , wherein only positive changes in pixel values are used to detect motion.
15. The method according to claim 13 , wherein only negative changes in pixel values are used to detect motion.
16. The method according to claim 13 , wherein both positive and negative changes in pixel values are used to detect motion.
17. The method according to claim 13 , wherein change across two pixels indicates local motion.
18. The method according to claim 13 , wherein the sum of correlated changes in pixel values across the field of view exceeding the predetermined threshold indicates sensor jitter.
19. The method according to claim 13 , wherein the sum of motion values within a subsection exceeds the predetermined threshold indicates the presence of an object larger than a predetermined size to be considered of interest.
20. The method according to claim 13 , wherein subsections of the field of view are defined by predetermined distances between sensor pixels.