Abstract: Embodiments relate to a MEMS IMU having an automatic gain control. The dynamic measurement range of the MEMS IMU is controlled by controlling the gain of a signal amplifier before the analog to digital converter (ADC) to make full use of the ADC range. In one embodiment, two or more MEMS inertial sensor sets are installed in the IMU. One of the sensor sets is for high accuracy with low dynamic range, and the other set or sets is for higher dynamic range with less resolution or accuracy. In one implementation, a digital processor determines which of the sensor sets to be used according to the system dynamic estimation. In another implementation, the system weights the sensor outputs from the sensor sets according to the system dynamics.

Abstract: A spatially distributed MEMS inertial sensor array is designed to reduce or cancel measurement errors and to increase the signal detection accuracy. By combining the measurements from a pair of sensors having sensing axes in two different, non-orthogonal directions, the correlated error due to the environmental changes are cancelled or reduced and the uncorrelated random noise is also reduced by the square root of two. By sequentially sampling the sensor array in the time domain, the number of the ADC circuits can be largely reduced. A two dimensional signal processing method is used to process the sensor array output data, in order to further reduce the remaining errors. Namely, one dimension uses the outputs from multiple spatially distributed sensor sets and the other dimension is the time domain. The signal to noise ratio is increased by using the signal correlation in both the spatial domain and the time domain.

Abstract: A system, a method and a computer readable storage medium for pre-processing data collected from one or more data sources more accurately summarize data. During the pre-processing, multiple raw data are summarized into a pre-processed datum. By using the pre-processed data entries, more accurate trend data may be generated. Alternatively, data entries are indexed and selectively retrieved based on indices. Decimation of data points are performed based on the indices without retrieving all the data sets from the database, reducing the data access time for returning a query result. Additional data sets may also be retrieved efficiently from the database using the indices.

Abstract: An antenna assembly for receiving the GPS signals in a global positioning system (GPS) receiver module automatically orients the antenna to better receive the GPS signals. The antenna is oriented by a positioner (e.g., a counterweight) that automatically rotates a frame on which the antenna is mounted. The GPS receiver module may also include multiple antennas oriented in different directions to maintain good reception of the GPS signals in any position. The multiple antennas are oriented in a manner so that the poor reception range an antenna is covered by other antennas. Signals from multiple antennas may be combined or chosen for processing by a GPS processor. Also, multiple GPS receiver modules may be deployed in close proximity so that wireless communication between the GPS receiver modules may be established.

Abstract: Method and apparatus for improving RF signal performance of a battery-operated handheld device includes RF isolating the battery from DC-powered circuitry and actively incorporating the battery in RF signal transfers with respect to an RF antenna.

Abstract: An antenna assembly for receiving the GPS signals in a global positioning system (GPS) receiver module automatically orients the antenna to better receive the GPS signals. The antenna is oriented by a positioner (e.g., a counterweight) that automatically rotates a frame on which the antenna is mounted. The GPS receiver module may also include multiple antennas oriented in different directions to maintain good reception of the GPS signals in any position. The multiple antennas are oriented in a manner so that the poor reception range an antenna is covered by other antennas. Signals from multiple antennas may be combined or chosen for processing by a GPS processor. Also, multiple GPS receiver modules may be deployed in close proximity so that wireless communication between the GPS receiver modules may be established. The GPS receiver modules with good GPS signals reception may determine its location and send its location information to the GPS modules with poor or no signal reception.

Abstract: An antenna assembly for receiving the GPS signals in a global positioning system (GPS) receiver module automatically orients the antenna to better receive the GPS signals. The antenna is oriented by a positioner (e.g., a counterweight) that automatically rotates a frame on which the antenna is mounted. The GPS receiver module may also include multiple antennas oriented in different directions to maintain good reception of the GPS signals in any position. The multiple antennas are oriented in a manner so that the poor reception range an antenna is covered by other antennas. Signals from multiple antennas may be combined or chosen for processing by a GPS processor. Also, multiple GPS receiver modules may be deployed in close proximity so that wireless communication between the GPS receiver modules may be established.

Abstract: An antenna assembly for receiving the GPS signals in a global positioning system (GPS) receiver module automatically orients the antenna to better receive the GPS signals. The antenna is oriented by a positioner (e.g., a counterweight) that automatically rotates a frame on which the antenna is mounted. The GPS receiver module may also include multiple antennas oriented in different directions to maintain good reception of the GPS signals in any position. The multiple antennas are oriented in a manner so that the poor reception range an antenna is covered by other antennas. Signals from multiple antennas may be combined or chosen for processing by a GPS processor. Also, multiple GPS receiver modules may be deployed in close proximity so that wireless communication between the GPS receiver modules may be established.

Abstract: Method and apparatus for improving RF signal performance of a battery-operated handheld device includes RF isolating the battery from DC-powered circuitry and actively incorporating the battery in RF signal transfers with respect to an RF antenna.

Abstract: Method and apparatus improve sensing accuracy and reduce bias shift in anisotropic magneto-resistive sensors using paired integrators and sampling switches for processing outputs of the sensor on applied set and reset signals with high immunity to temperature variations.

Abstract: A battery-monitoring circuit detects rapid changes in current drawn from a battery by a device powered thereby. The circuit includes calibrating operating modes that determine voltage-to-frequency conversion parameters, and amplifier errors at various levels of battery voltage.

Abstract: A method and system senses the attitude of an accelerating object by measuring acceleration with accelerometers in three orthogonal axes and measuring angular rate with angular rate sensors disposed about each such axis to compute attitude of the object accurately relative to a vertical axis. A processor updates a quaternion representation of attitude based upon the angular rate of the object, and a corrective rate signal is determined from level frame acceleration as a reference for a Kalman filter in calculating the attitude of the object. When velocity or airspeed is available from an external source, an aiding algorithm is employed to provide accurate attitude representations throughout all flight regimes.

Abstract: A plurality of modules interact to form an adaptive network in which each module transmits and receives data signals indicative of radio-frequency identification signals, and indicative of proximity sensing at the module. A central computer accumulates the data produced or received and relayed by each module for analyzing inventory, pricing and customer responses to transmit through the adaptive network signals representative of information to be displayed at selectively-addresses modules in response to computer analyses of the data accumulated from modules forming an adaptive network.

Abstract: A plurality of interactive modules are disposed at spaced locations to form an adaptive wireless network. Each module is capable of receiving transmissions of messages or data packets from other modules, and of transmitting messages or data packets to other modules for forming selected transmission paths via one or more modules toward a base station. Upon failure of a transmission path, a module not capable of transmitting a message along a transmission path toward the base station, transmits a message to other of the plurality of modules to form a new transmission path via such other module.

Abstract: A method and system senses the attitude of an accelerating object by measuring acceleration with accelerometers in three orthogonal axes and measuring angular rate with angular rate sensors disposed about each such axis to compute attitude of the object accurately relative to a vertical axis. A processor updates a quaternion representation of attitude based upon the angular rate of the object, and a corrective rate signal is determined from level frame acceleration as a reference for a Kalman filter in calculating the attitude of the object. When velocity or airspeed is available from an external source, an aiding algorithm is employed to provide accurate attitude representations throughout all flight regimes.

Abstract: A method and system updates a network of sensors remotely through the use of a communication link. The sensors to be updated as well as data files to perform the updating are selected at a base station. The selected sensors are notified of the upcoming update by the base station and may accept or reject the update. The sensors that approve the update then receive data files through the communication link. The sensors notify the base station of any missing data files, which are then retransmitted to all sensors that may be missing data files from the first transmission. After the sensors receive all data files, the update is initiated.

Abstract: A method and system senses the attitude of an accelerating object. Attitude sensing is accomplished by measuring acceleration in three orthogonal axes and measuring angular rate about each such axis to compute attitude accurately relative to a vertical axis. The system includes accelerometers and angular rate sensors for sensing the acceleration and the angular rate, respectively, of the object. A processor updates a quarternion representation of attitude based upon the angular rate of the object and a corrective rate signal to obtain the attitude of the object. Temperature compensation and frequency compensation may also be performed to update the quarternion.

Abstract: A three-dimensional position and orientation tracking system uses accelerometers to measure acceleration of a moveable object (e.g., a head-mounted display unit or a data glove). A tracking processor generates both position and orientation information on the object relative to a simulation environment as a function of the acceleration data. In one embodiment, a simplified radar-based tracking system is disposed relative to the object and periodically provides additional tracking data on the object to the tracking processor. The tracking processor uses the additional data to correct the position and orientation information using a feedback filter process. The position and orientation information signals generated can be used, for example, in a simulation or virtual reality application. Position and orientation information is received by a simulation processor relative to the object. The simulation processor modifies a simulation environment as a function of the position and orientation information received.

Abstract: A three-dimensional position and orientation tracking system uses accelerometers to measure acceleration of a moveable object (e.g., a head-mounted display unit or a data glove). A tracking processor generates both position and orientation information on the object relative to a simulation environment as a function of the acceleration data. In one embodiment, a simplified radar-based tracking system is disposed relative to the object and periodically provides additional tracking data on the object to the tracking processor. The tracking processor uses the additional data to correct the position and orientation information using a feedback filter process. The position and orientation information signals generated can be used, for example, in a simulation or virtual reality application. Position and orientation information is received by a simulation processor relative to the object. The simulation processor modifies a simulation environment as a function of the position and orientation information received.