DETECTING MOTION FOR A MULTIFUNCTION SENSOR DEVICE
First Claim
1. A processor-implemented method for detecting motion in a 3-D depth camera, comprising the processor-implemented steps of:
- obtaining acceleration readings in x-, y- and z-axes from a three-axis accelerometer in the 3-D depth camera at successive time points, and for each time point;
obtaining short and long term running averages of the acceleration readings in each axis of the x-, y- and z-axes;
obtaining differences between the short and long term running averages of the acceleration readings for each axis of the x-, y- and z-axes;
obtaining absolute values of the differences for each axis of the x-, y- and z-axes;
obtaining a sum based on the absolute values;
determining if the sum exceeds a threshold level;
if the sum exceeds the threshold level, providing an indication that movement of the 3-D depth camera is detected; and
if the sum does not exceed the threshold level, providing an indication that movement of the 3-D depth camera is not detected.
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Accused Products
Abstract
To detect movement of a depth camera in a motion capture system, readings from an accelerometer in the depth camera are processed to provide short and long term moving averages for each of the x, y and z axes. For each axis, a difference between the short and long term averages is obtained. A sum of the differences is obtained by summing the absolute value of each difference, across all three axes. This sum of differences is then compared to a threshold to determine if movement is detected. In another approach, the short and long term averages of the accelerometer readings are converted to pitch and roll values, and the pitch and roll values are separately compared to a threshold to determine if movement is detected. A tracking algorithm can be temporarily halted while movement is detected. Readings in the vertical direction can be attenuated by a scaling factor.
42 Citations
20 Claims
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1. A processor-implemented method for detecting motion in a 3-D depth camera, comprising the processor-implemented steps of:
obtaining acceleration readings in x-, y- and z-axes from a three-axis accelerometer in the 3-D depth camera at successive time points, and for each time point; obtaining short and long term running averages of the acceleration readings in each axis of the x-, y- and z-axes; obtaining differences between the short and long term running averages of the acceleration readings for each axis of the x-, y- and z-axes; obtaining absolute values of the differences for each axis of the x-, y- and z-axes; obtaining a sum based on the absolute values; determining if the sum exceeds a threshold level; if the sum exceeds the threshold level, providing an indication that movement of the 3-D depth camera is detected; and if the sum does not exceed the threshold level, providing an indication that movement of the 3-D depth camera is not detected. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. Tangible computer readable storage having computer readable software embodied thereon for programming at least one processor to perform a method for detecting motion in a 3-D depth camera, the method comprising:
obtaining time points of acceleration readings in x-, y- and z-axes from a three-axis accelerometer in the 3-D depth camera, and for each time point; obtaining short and long term running averages of the acceleration readings in each axis of the x-, y- and z-axes; based on the short and long term running averages of the acceleration readings;
obtaining short and long term change in pitch values of the 3-D depth camera, and short and long term change in roll values of the 3-D depth camera;obtaining differences between the short and long term change in pitch values; obtaining absolute values of the differences between the short and long term change in pitch values; obtaining differences between the short and long term change in roll values; obtaining absolute values of the differences between the short and long term change in roll values; determining if a threshold is exceeded by at least one of;
(a) the absolute values of the differences between the short and long term change in pitch values and (b) the absolute values of the differences between the short and long term change in roll values; andproviding an indication that movement of the 3-D depth camera is detected when the threshold is exceeded. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A motion capture system, comprising:
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a 3-D depth camera having a field of view, and including at least one three-axis accelerometer; a display; and one or more processors associated with the 3-D depth camera, the one or more processors execute instructions to track movement of a user in the field of view and to provide a signal to the display to display images based on the tracked movement; wherein the one or more processors;
(a) to detect movement of the 3-D depth camera, obtain short and long term running averages from the at least one three-axis accelerometer, determine differences between the short and long term running averages, obtain a sum based on the differences, and compare the sum to a threshold level, and (b) temporarily suspend the tracking of the movement of the user in response to the indication that movement of the 3-D depth camera is detected. - View Dependent Claims (17, 18, 19, 20)
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Specification