Abstract: An identity certificate may be issued to a blockchain node. The issuance may include issuing a first identity certificate to a first terminal and receiving a second identity certificate issuance request that is from the first terminal. A second identity certificate may be issued to the first terminal, and a third identity certificate issuance request is received from the second terminal. A third identity certificate is issued to the second terminal, so that the second terminal forwards the third identity certificate to the third terminal.

Abstract: A battery status indication method, A battery status indication apparatus, and a mobile device are provided. The battery status indication method includes: obtaining a power level and a heat state of a battery, the heat state including an unheated state and a heating state; determining a display mode of indicator lights according to the power level and the heat state of the battery; and controlling the indicator lights to display according to the display mode to indicate the power level and the heat state of the battery.

Abstract: A gimbal assembly includes a body and a gimbal frame movably connected with the body. The gimbal frame is configured to completely fit with the body or partially fit with the body through a sliding mechanism to reduce a volume of the gimbal assembly. The sliding mechanism includes a first sliding member disposed at the body and a second sliding member disposed at the gimbal frame to match with the first sliding member, such that the gimbal frame slides from an extended position to a receiving position with respect to the body.

Abstract: A method for generating sound with a motor, including: generating a motor-driving signal having an audio signal component; applying the motor-driving signal to the motor, wherein the motor-driving signal drives the motor to generate a sound corresponding to the audio signal component; applying a bandpass filter to the motor-driving signal to generate a filtered motor-driving signal; and applying the filtered motor-driving signal to a speaker to present audio content consistent with the sound generated by the motor.

Abstract: An encoder includes a code disc and a processor communicatively coupled with the code disc. The code disc is configured to rotate along with a rotating object and includes a plurality of fan teeth extending radially. One of the plurality of fan teeth is different from other ones of the plurality of fan teeth, and the other ones of the fan teeth are same to each other. A first portion of a detection signal that is generated in one rotation of the code disc, corresponding to the one of the plurality of fan teeth, is different from a second portion of the detection signal, corresponding to each of the other ones of the fan teeth. The processor is configured to detect the rotation of the code disc to obtain the detection signal and a rotation parameter of the rotating object based on the detection signal.

Abstract: A method for controlling a motor configured to provide propulsion for a mobile platform includes determining whether to activate a preheat mode based on a temperature of a motor and, upon determining to activate the preheat mode, controlling a preheat current provided to the motor to enable self-preheating of the motor.

Abstract: A method for controlling a motor includes obtaining addressing information of an electronic speed governor coupled to the motor, determining a rotation direction of the motor based on the addressing information, and providing a drive signal to the motor according to the rotation direction.

Abstract: A detection system includes a control circuit, a control system, and a detection circuit. The control circuit is configured to control on-off of a battery cell. An input end of the control circuit is configured to be connected to the battery cell, and an output end of the control circuit is configured to be connected to a battery connection device. The control system is configured to be connected to the battery connection device and to control the battery cell to supply power to the control system via the battery connection device. The detection circuit is connected to the control circuit or the control system and is configured to detect a parameter value of the battery connection device. The control circuit or the control system is further configured to determine health status of the battery connection device according to the parameter value of the battery connection device.

Abstract: A battery control circuit includes a switch control unit, a voltage conversion circuit, and a port. The switch control circuit is configured to control turning-on and turning-off of a battery cell and the voltage conversion circuit. A first terminal of the voltage conversion circuit is connected to the switch control circuit and the other terminal of the voltage conversion circuit is connected to the port. The port is configured to connect an external device. The voltage conversion circuit is configured to convert a voltage of one of the battery cell and the external device to charge the other one of the battery cell and the external device.

Abstract: An unmanned aerial vehicle includes a fuselage, a motor mounted at the fuselage, and a control apparatus configured to control the motor. The control apparatus includes one or more processors configured to obtain a present electrical parameter of a battery configured to power the motor, calculate a compensation amount of a control signal of the motor according to the present electrical parameter, and modify the control signal according to the compensation amount.

Abstract: A gimbal assembly includes a body and a gimbal frame movably connected with the body. The gimbal frame is configured to completely fit with the body or partially fit with the body through a sliding mechanism to reduce a volume of the gimbal assembly. The sliding mechanism includes a first sliding member disposed at the body and a second sliding member disposed at the gimbal frame to match with the first sliding member, such that the gimbal frame slides from an extended position to a receiving position with respect to the body.

Abstract: Systems, apparatuses and methods for indicating a moveable device such as an unmanned aerial vehicle (UAV) are disclosed herein. The present technology provides an illumination system having a light source and an illuminating component. In a representative embodiment, the light source is carried by a UAV and positioned to emit a light ray in a first direction. The illuminating component is carried by a propeller of the UAV. The illuminating component can include a light entrance portion, a light transmission portion, and a light exit portion. The light entrance portion is positioned to receive the light ray from the light source, the light transmission portion is positioned to transmit the light ray to the light exit portion, and the light exit portion is positioned to direct the light ray in a second direction so as to form a visual indication corresponding to the UAV.

Abstract: A battery status indication method, A battery status indication apparatus, and a mobile device are provided. The battery status indication method includes: obtaining a power level and a heat state of a battery, the heat state including an unheated state and a heating state; determining a display mode of indicator lights according to the power level and the heat state of the battery; and controlling the indicator lights to display according to the display mode to indicate the power level and the heat state of the battery.

Abstract: A gimbal photographing device includes a machine body, a foldable mechanism connected with the machine body, and a gimbal camera connected with the foldable mechanism. The gimbal camera is configured to cling to the machine body through the foldable mechanism and to be positioned in an extended state or a folded state. The machine body includes a support wall configured to support the gimbal camera. The foldable mechanism includes a rotation member rotatably connected with the support wall around a rotation axis direction to cause the gimbal camera to rotate relative to the machine body. The rotation member is configured to cause the gimbal camera to rotate to the folded state in which the gimbal camera clings to the support wall.

Abstract: A detachable control device includes an operation member, a detachable interface configured to attach the detachable control device to a handle of a gimbal device, a wireless communication circuit, and a controller configured to detect an operation on the operation member, and generate control data according to the operation. The control data includes at least one of gimbal orientation control data for controlling an attitude of a gimbal of the gimbal device or camera function control data for controlling a photographing device mounted at the gimbal to perform a corresponding function. If the detachable control device is not attached to the handle, the controller sends the control data to at least one of the gimbal device or the photographing device through the wireless communication circuit.

Abstract: An encoder includes a code disc and a processor communicatively coupled with the code disc. The code disc is configured to rotate along with a rotating object and includes a plurality of fan teeth extending radially. One of the plurality of fan teeth is different from other ones of the plurality of fan teeth, and the other ones of the fan teeth are same to each other. A first portion of a detection signal that is generated in one rotation of the code disc, corresponding to the one of the plurality of fan teeth, is different from a second portion of the detection signal, corresponding to each of the other ones of the fan teeth. The processor is configured to detect the rotation of the code disc to obtain the detection signal and a rotation parameter of the rotating object based on the detection signal.

Abstract: A method of controlling a motor includes determining a first motor controlling parameter measurement based on a signal received from a position sensor, determining a second motor controlling parameter based on one or more motor electrical parameters, and controlling operation of the motor based on at least one of the first motor controlling parameter measurement or the second motor controlling parameter measurement.

Abstract: A gimbal photographing device includes a machine body, a foldable mechanism connected with the machine body, and a gimbal camera connected with the foldable mechanism. The gimbal camera is configured to cling to the machine body through the foldable mechanism, and is configured to be positioned in an extended state or a folded state. The machine body includes a support wall configured to support the foldable mechanism and the gimbal camera. The foldable mechanism includes a base including a rotation member and a position limiting member connected with the rotation member. The position limiting member is connected with the gimbal camera. The position limiting member includes a first end and a second end that are opposingly disposed. The rotation member is rotatably connected with the support wall around a rotation axis direction to cause the gimbal camera to rotate relative to the machine body.

Abstract: A method for driving an electric motor includes providing two controllers for driving the electric motor. The two controllers use different control methods to drive the electric motor. The method further includes selecting a first controller of the controllers as a primary controller to drive the electric motor and a second controller of the controllers as a secondary controller, monitoring a control of the electric motor, and switching the control of the electric motor from the primary controller to the secondary controller if an error condition is detected in the control of the electric motor.

Abstract: A gimbal assembly includes a body and a gimbal frame movably connected with the body. The gimbal frame is configured to fittingly contact the body or to be at least partially received in the body to reduce a volume of the gimbal assembly.