The United States of America as Represented by the Administrator of the National Aeronautics and Patent applications |
Patent application number | Title | Published |
20110190934 | ARCHITECTURE FOR ROBUST FORCE AND IMPEDANCE CONTROL OF SERIES ELASTIC ACTUATORS - An SEA architecture for controlling the torque applied by an SEA that has particular application for controlling the position of a robot link. The SEA architecture includes a motor coupled to one end of an elastic spring and a load coupled to an opposite end of the elastic spring, where the motor drives the load through the spring. The orientation of the shaft of the motor and the load are measured by position sensors. Position signals from the position sensors are sent to an embedded processor that determines the orientation of the load relative to the motor shaft to determine the torque on the spring. The embedded processor receives reference torque signals from a remote controller, and the embedded processor operates a high-speed servo loop about the desired joint torque. The remote controller determines the desired joint torque based on higher order objectives by their impedance or positioning objectives. | 08-04-2011 |
20100329585 | Spatial standard observer - The present invention relates to devices and methods for the measurement and/or for the specification of the perceptual intensity of a visual image, or the perceptual distance between a pair of images. Grayscale test and reference images are processed to produce test and reference luminance images. A luminance filter function is convolved with the reference luminance image to produce a local mean luminance reference image. Test and reference contrast images are produced from the local mean luminance reference image and the test and reference luminance images respectively, followed by application of a contrast sensitivity filter. The resulting images are combined according to mathematical prescriptions to produce a Just Noticeable Difference, JND value, indicative of a Spatial Standard Observer, SSO. Some embodiments include masking functions, window functions, special treatment for images lying on or near borders and pre-processing of test images. | 12-30-2010 |
20100306159 | CONTACT STATE ESTIMATION FOR MULTI-FINGER ROBOT HANDS USING PARTICLE FILTERS - A method for identifying the location, orientation and shape of an object that a robot hand touches that includes using a particle filter. The method includes defining an appropriate motion model and a measurement model. The motion model characterizes the motion of the robot hand as it moves relative to the object. The measurement model estimates the likelihood of an observation of contact position, velocity and tactile sensor information given hand-object states. The measurement model is approximated analytically based on a geometric model or based on a corpus of training data. In either case, the measurement model distribution is encoded as a Gaussian or using radial basis functions. | 12-02-2010 |