Abstract: A method and device for acquiring a rotor position based on a permanent magnet synchronous drive system. The permanent magnet synchronous drive system includes an inverter and a permanent magnet synchronous motor, wherein the initial speed of the permanent magnet synchronous motor is not zero. The method includes: controlling a bridge arm switch of an inverter periodically; collecting a three-phase current of the permanent magnet synchronous motor at a fixed time within each control period; and after the three-phase current is reversed, sending same to a phase-locked loop system to conduct processing, so as to obtain a phase angle of an induction potential vector, and according to the phase angle of the induction potential vector, acquiring a rotor position angle of the permanent magnet synchronous motor.

Abstract: A control method for restarting a permanent magnet synchronous motor (PMSM) in a rotating condition, and a device and a system thereof are provided. In the method, an electrical angular speed ?e of the PMSM is obtained based on a speed of a trailer to obtain a back electromotive force of the PMSM. The back electromotive force is compared with a voltage at a side of an inverter, and if the electromotive force of the permanent magnet synchronous motor is higher than the voltage at the side of the inverter, the restarting of the PMSM is forbidden, otherwise, the restarting of the PMSM is allowed. Therefore, in the present disclosure, the low-speed operating condition and the high-speed operating condition correspond to different position angles of the rotor, and the PMSM is started based on the position angle of the rotor.

Abstract: A direct-axis current protection method and device for a permanent magnet synchronous motor drive system. The method includes: pre-calculating the direct-axis current of the next moment according to the current voltage transmitted from an inverter to a permanent magnet synchronous motor (PMSM); comparing the direct-axis current of the next moment with a maximum protection current; if the direct-axis current of the next moment is less than the maximum protection current, continuing transmitting the current voltage to the PMSM; if the direct axis current of the next moment is greater than or equal to the maximum protection current, redistributing the voltage according to a protection direct-axis current and a protection quadrature-axis current, and transmitting the redistributed voltage to the PMSM. The direct-axis current of the next moment is tended to be normal by adjusting the voltage.

Abstract: The present invention discloses a method and system for implementing power detection, wherein said method includes: extracting basic information of a destination base station from a detection request, obtaining configuration information of said destination base station from a database according to the basic information, and searching available signal transmission links and power collection points of said destination base station according to the configuration information; carrying out power collection, and analyzing power values of each available power collection point on the available signal transmission link, and updating the power values of corresponding power collection points. With the present invention, power detection can be carried out on the device from a perspective of the system, and the maintainability and operability are improved.

Abstract: The present invention discloses a method and system for implementing power detection, wherein said method includes: extracting basic information of a destination base station from a detection request, obtaining configuration information of said destination base station from a database according to the basic information, and searching available signal transmission links and power collection points of said destination base station according to the configuration information; carrying out power collection, and analyzing power values of each available power collection point on the available signal transmission link, and updating the power values of corresponding power collection points. With the present invention, power detection can be carried out on the device from a perspective of the system, and the maintainability and operability are improved.

Abstract: System and method for a flyable and roadable vehicle. According to an embodiment, the present invention provides a vehicle capable of air and road travel. The vehicle is adaptable to a flying configuration and a road configuration. The vehicle includes a fuselage having a front end, a rear end, a top side, a bottom side. The vehicle also includes a wing component having a plurality of planes. The plurality of planes includes a first plane and a second plane. The vehicle additionally includes a connecting component for coupling the planes of the wing and the fuselage. The connecting component is able to accommodate a substantial relative rotation between the first plane and the fuselage. The vehicle further includes a plurality of wheels coupled to the bottom side of the fuselage.

Abstract: System and method for a flyable and roadable vehicle. According to an embodiment, the present invention provides a vehicle capable of air and road travel. The vehicle is adaptable to a flying configuration and a road configuration. The vehicle includes a fuselage having a front end, a rear end, a top side, a bottom side. The vehicle also includes a wing component having a plurality of planes. The plurality of planes includes a first plane and a second plane. The vehicle additionally includes a connecting component for coupling the planes of the wing and the fuselage. The connecting component is able to accommodate a substantial relative rotation between the first plane and the fuselage. The vehicle further includes a plurality of wheels coupled to the bottom side of the fuselage.

Abstract: Apparatus and methods of differentially decoding analog baseband signals are described. In one aspect, a wireless communication apparatus includes a baseband filtering stage and a differential decoder stage. The baseband filtering stage receives a DPSK analog baseband signal differentially encoded with phase shift differences in successive symbol periods. The baseband filtering stage selectively passes frequencies in the DPSK analog baseband signal within a passband frequency range to produce a filtered analog signal. The differential decoder includes a delay circuit and a combiner circuit. The delay circuit produces from the filtered analog signal a reference signal that preserves values of a feature of the filtered analog signal for one symbol period. The combiner circuit combines values of a feature of the filtered analog signal during a current symbol period with values of the reference signal to produce a resultant signal representing a differential decoding of the DPSK analog baseband signal.