1. A satellite signal tracking method comprising:
receiving a satellite signal from a positioning satellite;
receiving a measurement of a situation of movement from at least one sensor;
calculating an error of the measurement;
determining a jitter of a tracking loop circuit, the jitter including a dynamic stress, the dynamic stress being calculated based on the measurement of the situation of movement and the error of the measurement, and the tracking loop circuit being used to track the received satellite signal; and
setting a loop bandwidth of the tracking loop circuit based on the jitter.
2. The satellite signal tracking method according to claim 1, wherein the at least one sensor includes one of an acceleration sensor, a velocity sensor, and a gyro sensor, and
wherein the error of the measurement is calculated based on an amount of time that has elapsed since the at least one sensor was calibrated.
3. The satellite signal tracking method according to claim 1, wherein the setting of the loop bandwidth includes setting the loop bandwidth based on a temperature of the satellite signal reception environment or a signal strength of the satellite signal.
4. The satellite signal tracking method according to claim 1, wherein the setting of the loop bandwidth includes setting the loop bandwidth based on a filter order of the tracking loop circuit.
5. A position calculating method comprising:
tracking the satellite signal by performing the satellite signal tracking method according to claim 1; and
calculating a position using the tracked satellite signal.
6. A position calculating device comprising:
at least one sensor selected from an acceleration sensor, a velocity sensor, and a gyro sensor;
a movement situation detecting unit that detects a situation of movement using an output of the at least one sensor;
a tracking loop circuit that is used to track a satellite signal from a positioning satellite and of which a loop bandwidth can be changed;
a jitter determination unit that determines a jitter of the tracking loop circuit, the jitter including a dynamic stress that is calculated based on the detection result of the movement situation detecting unit and a detection error of the detection result;
a loop bandwidth setting unit that sets the loop bandwidth of the tracking loop circuit based on the jitter; and
a position calculating unit that calculates a position using the satellite signal tracked by the tracking loop circuit.
7. The satellite signal tracking method of claim 1, wherein the loop bandwidth of the tracking loop circuit is set to a bandwidth value for adjusting the jitter to be less than or equal to a predetermined threshold.
8. The satellite signal tracking method of claim 1, wherein the loop bandwidth of the tracking loop circuit is set to a bandwidth value for minimizing the jitter.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A simple zero current switch circuit to control a conduction switch of a power-factor corrector in a zero current condition during ONOFF switching operations, the power-factor corrector including an energy storing inductor to receive a commutated electric power and store energy and perform discharging, an output diode and an output capacitor electrically bridging the energy storing inductor and a power output end, and a conduction switch and a controller electrically bridging the energy storing inductor and the output diode, the zero current switch circuit comprising:
a first coil set bridging the energy storing inductor and the output diode, the first coil set being connected to the conduction switch through a second coil set which is wound reversely according to a selected coil ratio relative to the first coil set, the first coil set having a leaking inductance to generate a back electromotive force to make the conduction switch in a zero current switching condition during ONOFF operations; and
an energy conversion circuit which is coupled with the power-factor corrector, the first coil set and the second coil set to form a power circuit, the energy conversion circuit including a plurality of diodes, capacitors, and a resistor; while the output diode generating a reverse recovery condition, the energy conversion circuit stores reverse energy according to the coil ratio of the second coil set relative to the first coil set and reclaims the energy to the output capacitor, thereby reverse recovery time of the output diode is shortened.
2. The simple zero current switch circuit of claim 1, wherein the first coil set and the second coil set are wound in reverse directions.