摘要:
An apparatus and method to enhance dead-reckoning navigation using inertial sensor measurements based on images from a camera are disclosed. A camera build into a mobile device is used to calibrate inertial sensors and rotation matrices. Images from a camera may be used (1) to remove a gravitational element from accelerometer measurements; (2) to set a scaling factor and an offset for a gyrometer; and (3) to set initial and updated values for rotation matrices.
摘要:
A satellite based positioning method and system including storing satellite sub-almanac data on a mobile station. Embodiments include using the sub-almanac data to take measurements and calculate a coarse position of the mobile station. Embodiments further include a location server calculating a correction to the coarse position, and the location server determining whether any sub-almanacs used to calculate the coarse position require replacement.
摘要:
Devices and methods are described for determining position information without broadcast ephemeris data for extended time periods. A server or client device receives or collects historical state data of satellites of a satellite-based positioning system and generates predictions of future satellite trajectories for future time periods. When a server generates the predictions, the predictions are subsequently transferred to a client device. The client device selects predictions appropriate to time of interest. The time can be any time during a period of at least seven calendar days. The client device reconstructs satellite states using information on the predictions and uses the reconstructed satellite states to acquire satellite signals as appropriate to the current location and time of the client device. The client device determines and/or tracks its position using information of the satellite states and timing information of the satellite signals.
摘要:
An apparatus and method for estimating a position of a mobile device based on one or more images is disclosed. Positioning information is derived from an image containing an SAS (self-addressing source such as a QR code), thereby setting a first vector V1 and an SAS pose. The image is also used to determine a displacement between the mobile device and the self-addressing source, thereby setting a second vector V2. Using the first vector V1, the SAS pose and the second vector V2, the mobile device may estimate its position with high accuracy and may also recalibrate dead-reckoning navigation and a gyrometer.
摘要:
An apparatus and method for a personal navigation apparatus comprising a personal navigation device (PND) for providing navigational guidance information. The PND may include a single-dimensional magnetic detector for sensing magnetic flux amplitudes of a magnetic field generated by a magnet. Alternatively, the PND may include a three-dimensional magnetic detector and a magnetic calibration module for determining an ambient magnetic field calibration value representing immediate surroundings of the PND.
摘要:
A satellite based positioning method and system including storing satellite sub-almanac data on a mobile station. Embodiments include using the sub-almanac data to take measurements and calculate a coarse position of the mobile station. Embodiments further include a location server calculating a correction to the coarse position, and the location server determining whether any sub-almanacs used to calculate the coarse position require replacement.
摘要:
The initialization of an inertial navigation system is performed using information obtained from an image of an object. Positional and orientational information about the object in a global reference frame and positional and orientational information about the camera relative to the object are obtained from the image. Positional and orientational information for the camera in the global reference frame is determined along with a transformation matrix between inertial sensor reference frame and a navigation coordinate frame. The inertial navigation system is initialized using the positional and orientational information for the camera, the transformation matrix and the velocity of the camera when the object was imaged, i.e., zero. Using the initialized data with measurements from the inertial sensors the position of the mobile platform may be updated during navigation and provided, e.g., on a digital map. Inertial navigation errors may be corrected using information obtained from images of different objects.
摘要:
A power management system for managing power in a wireless device having a SPS receiver, communication device and a power source, the power management is described. The power management system may include a real-time clock, an input/output device, a radio frequency front-end and a SPS engine in signal communication with the real-time clock, input/output device and radio frequency front-end, the SPS engine capable of powering down itself, the input/output device and radio frequency front-end in response to determining a mode of operation.
摘要:
Devices and methods are described for determining position information without broadcast ephemeris data for extended time periods. A server or client device receives or collects historical state data of satellites of a satellite-based positioning system and generates predictions of future satellite trajectories for future time periods. When a server generates the predictions, the predictions are subsequently transferred to a client device. The client device selects predictions appropriate to time of interest. The time can be any time during a period of at least seven calendar days. The client device reconstructs satellite states using information on the predictions and uses the reconstructed satellite states to acquire satellite signals as appropriate to the current location and time of the client device. The client device determines and/or tracks its position using information of the satellite states and timing information of the satellite signals.