Abstract: An all-terrain vehicle includes a frame, wheels, a vehicle cover, a power supply system a saddle assembly, a brake system, a drive assembly and a suspension system. The all-terrain vehicle is sized for children to ride, with numerous disclosed modifications in accordance with its size and riders. For instance, the saddle assembly includes a locking hook accessible from the rear of the vehicle, and in the locked state holds the main power supply down into its compartment. The brake system uses a pawl for two handed setting of the parking brake. The instrument assembly allows adjustment of the display angle of the display screen. The charger cover uses a damping block to cause the cover to hover at a selected position. The all-terrain vehicle can meet the use needs and safety requirements of all-terrain vehicles for kids, and can ensure the safety of drivers.

Abstract: A rotor temperature monitoring method and system for a permanent magnet synchronous motor are provided. According to the method and system, an a-phase line current and a b-phase line current of a stator of a permanent magnet synchronous motor are obtained as a first line current and a second line current; further, a line voltage between the a-phase and the b-phase of the stator is obtained and a rotating speed of the rotor of the permanent magnet synchronous motor is obtained; and then, the first line current, the second line current, the line voltage, the rotating speed of the rotor, an inductance parameter of the permanent magnet synchronous motor and a temperature characteristic equation of a permanent magnet of the rotor are substituted into a preset rotor permanent magnet temperature expression to calculate and obtain the temperature of the rotor.

Abstract: A method and a system for correcting an initial zero position deviation are provided, which is applied to a permanent magnet synchronous motor and a resolver. The method includes: driving a rotor of the permanent magnet synchronous motor to rotate at a constant speed; acquiring counter electromotive forces of a stator of the permanent magnet synchronous motor and a position of a rotor of the resolver; calculating a space vector phase angle ?1 based on the counter electromotive forces; acquiring a rotation angle ?2 measured by the resolver; calculating an installation deviation ?? corresponding to the space vector phase angle ?1 and the rotation angle ?2; and adjusting a position of the resolver until the installation deviation ?? meets a precision requirement.

Abstract: A method and a system for correcting an initial zero position deviation are provided, which is applied to a permanent magnet synchronous motor and a resolver. The method includes: driving a rotor of the permanent magnet synchronous motor to rotate at a constant speed; acquiring counter electromotive forces of a stator of the permanent magnet synchronous motor and a position of a rotor of the resolver; calculating a space vector phase angle ?1 based on the counter electromotive forces; acquiring a rotation angle ?2 measured by the resolver; calculating an installation deviation ?? corresponding to the space vector phase angle ?1 and the rotation angle ?2; and adjusting a position of the resolver until the installation deviation ?? meets a precision requirement.

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 rotor temperature monitoring method and system for a permanent magnet synchronous motor are provided. According to the method and system, an a-phase line current and a b-phase line current of a stator of a permanent magnet synchronous motor are obtained as a first line current and a second line current; further, a line voltage between the a-phase and the b-phase of the stator is obtained and a rotating speed of the rotor of the permanent magnet synchronous motor is obtained; and then, the first line current, the second line current, the line voltage, the rotating speed of the rotor, an inductance parameter of the permanent magnet synchronous motor and a temperature characteristic equation of a permanent magnet of the rotor are substituted into a preset rotor permanent magnet temperature expression to calculate and obtain the temperature of the rotor.

Abstract: A terminal device is described that includes a housing configured to accommodate various components of the terminal device; a first sensing unit configured to collect first status information of the terminal device; a second sensing unit configured to collect second status information of the terminal device; and a processing unit configured to determine a manner that a user holds the terminal device based on the first status information and the second status information.

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 terminal device is described that includes a housing configured to accommodate various components of the terminal device; a first sensing unit configured to collect first status information of the terminal device; a second sensing unit configured to collect second status information of the terminal device; and a processing unit configured to determine a manner that a user holds the terminal device based on the first status information and the second status information.