The invention discloses a method and corresponding device for taming crystal oscillation frequency of a time-keeping device, which comprises the following steps of: step 1, acquiring the standard time pulse A that is located and output by a navigation satellite; step 2, acquiring the standard time pulse B output by device crystal oscillation fractional frequency; step 3, measuring the clock difference between the standard time pulse A and the standard time pulse B; and step 4, if clock difference exists between A and B, adjusting the crystal oscillation frequency of the device to make the clock difference be in the allowed scope. For the time-keeping equipment with pressure control and temperature compensating crystal oscillation or pressure control crystal oscillation, the frequency deviation of the corrected crystal oscillation can be detected in real time by the method provided by the invention to eliminate the time-keeping error caused by crystal oscillation frequency deviation and avoid accumulation of error. Therefore, the invention is suitable for various satellite navigation systems, such as GPS, Beidou first generation navigation satellite, Beidou second generation navigation satellite, GLONASS, GALILEO and other satellite navigation systems.

Method and corresponding device for taming crystal oscillation frequency of time-keeping device

Methods and systems may provide for determining a status of a mobile platform, wherein the status indicates whether the mobile platform is stationary, and adapting a detection schedule of one or more location sensors on the mobile platform based at least in part on whether the mobile platform is stationary. Additionally, one or more location updates may be generated based at least in part on information from the one or more location sensors. In one example, a location request is received, wherein the detection schedule is adapted further based on quality of service (QoS) information associated with the location request, and wherein the one or more location updates are generated in response to the location request.

Situation aware sensor power management

A timing signal generating device includes a GPS receiver and a processing unit. The GPS receiver functions as a positioning calculation unit, and receives satellite signals transmitted from GPS satellites and performs positioning calculation based on trajectory information and time information contained in the received satellite signals. Further, the processing unit functions as a position information generation unit, and generates position information of a receiving point based on a mode value or a median value in results of the positioning calculation at a plurality of times by the GPS receiver.

Timing signal generating device, electronic apparatus, moving object, method of generating timing signals, and method of controlling satellite signal receiver

PROBLEM TO BE SOLVED: To provide a position information generation device and a timing signal generation device less affected by a positioning result containing a large error even when an error in positioning calculation increases due to the degradation of a reception environment and capable of generating a more accurate timing signal than before, and to provide a high-reliability electronic apparatus and mobile body equipped with this timing signal generation device.SOLUTION: A timing signal generation device 1 includes a GPS receiver 10 for performing positioning calculation on the basis of a satellite signal, and a DSP 23 for generating the position information of a reception point on the basis of a value that is within the range A±σ/4 where A is the mode or median of a plurality of positioning calculation results of the GPS receiver 10 and σ is the standard deviation of the plurality of positioning calculation results, the timing signal generation device 1 generating a timing signal on the basis of a satellite signal from at least one position information satellite and the position information of the reception point.

Position information generation device, timing signal generation device, electronic apparatus, and moving object

This synchronization device has a normal-signal generator, a reference-signal generator, and a phase difference detector. The normal-signal generator generates a normal signal having a timing synchronized with a time signal from a satellite. The reference-signal generator generates a reference signal having a timing synchronized with a received signal. The phase difference detector detects the phase difference between the reference signal and the normal signal. The normal-signal generator controls the normal signal on the basis of the phase difference when the time signal cannot be obtained.

Synchronization device and synchronization method

PROBLEM TO BE SOLVED: To provide a time device for reducing adjustment costs with low electric power consumption while maintaining the required time accuracy. SOLUTION: An error of an oscillation frequency of a voltage controlled crystal oscillator 15 is measured by frequency error measurement parts 12, 13a on the basis of a reference one-second pulse from a GPS receiver 11. A control part 13 controls a control voltage of a D/A converter 14 on the basis of the measurement results, and repeats a frequency calibration operation for the voltage controlled crystal oscillator 15 at a time interval. Each time when the frequency calibration operation is finished, control voltage data are associated with the temperature of the voltage controlled crystal oscillator 15 and stored in a nonvolatile memory 17 as temperature compensation data. In a duration excluding the time of the frequency calibration operation, a power supply of the GPS receiver 11 is turned off by a power supply control circuit 19. In the duration excluding the time of the frequency calibration operation, the control voltage data corresponding to the current temperature of the voltage controlled crystal oscillator 15 are output from the control part 13 to the D/A converter 14 on the basis of the temperature compensation data. COPYRIGHT: (C)2010,JPO&INPIT

Takahisa Iio

Papers

Time device and portable electronic apparatus