The present disclosure discloses a method for braking a permanent magnet synchronous motor and a related device. The method is applied to an electronic speed controller and includes: receiving a signal for braking the permanent magnet synchronous motor sent by a flight controller; sending a first control signal to the permanent magnet synchronous motor, the first control signal being used to control the permanent magnet synchronous motor to decrease its rotational speed to a preset rotational speed range within a first preset time period; and after the first preset time period ends, sending a second control signal to the permanent magnet synchronous motor, the second control signal being used to control the permanent magnet synchronous motor to stop rotating within a second preset time period. According to the method, consistency of shutdown of multiple motors is ensured, and use experience of a drone is improved.

The present disclosure discloses a method for braking a permanent magnet synchronous motor and a related device. The method is applied to an electronic speed controller and includes: receiving a signal for braking the permanent magnet synchronous motor sent by a flight controller; sending a first control signal to the permanent magnet synchronous motor, the first control signal being used to control the permanent magnet synchronous motor to decrease its rotational speed to a preset rotational speed range within a first preset time period; and after the first preset time period ends, sending a second control signal to the permanent magnet synchronous motor, the second control signal being used to control the permanent magnet synchronous motor to stop rotating within a second preset time period. According to the method, consistency of shutdown of multiple motors is ensured, and use experience of a drone is improved.

A door closer system is provided that includes a motor, a spring, a reduction gear set, and a rack and a pinion mechanism. The spring and pinion may be coupled to the rack, and the pinion may be selectively coupled to the gear set. The motor may be selectively mechanically coupled to the gear set. The pinion may rotate in a first direction via the rack as the spring is compressed in a second direction opposite the first direction as the spring is expanded. The motor is operable to rotate and act upon the pinion through the gear set, thereby rotating the pinion in the second direction and assist the spring in closing the door.

A door closer system is provided that includes a motor, a spring, a reduction gear set, and a rack and a pinion mechanism. The spring and pinion may be coupled to the rack, and the pinion may be selectively coupled to the gear set. The motor may be selectively mechanically coupled to the gear set. The pinion may rotate in a first direction via the rack as the spring is compressed in a second direction opposite the first direction as the spring is expanded. The motor is operable to rotate and act upon the pinion through the gear set, thereby rotating the pinion in the second direction and assist the spring in closing the door.

A multi-disk brake system comprises an electrical generator disposed therein. The electrical generator is configured to convert mechanical energy to electrical energy. The mechanical energy may be generated during a braking event of the multi-disk brake system. The electric generator may power various electrical components on the aircraft or store the electrical energy in a capacitor bank. The electric generator may also act as a motor and/or power a landing gear in a motor configuration.

A multi-disk brake system comprises an electrical generator disposed therein. The electrical generator is configured to convert mechanical energy to electrical energy. The mechanical energy may be generated during a braking event of the multi-disk brake system. The electric generator may power various electrical components on the aircraft or store the electrical energy in a capacitor bank. The electric generator may also act as a motor and/or power a landing gear in a motor configuration.

A drive system comprises a DC-DC converter that is arranged to receive an input voltage from a battery having a nominal battery voltage. The DC-DC converter has a first mode of operation in which the DC-DC converter generates a regulated output voltage from the input voltage and supplies the regulated output voltage to a load, and a second mode of operation in which the DC-DC converter is by-passed such that the input voltage from the battery is supplied to the load. A controller is arranged to compare the input voltage to a threshold voltage that is less than the nominal battery voltage. The controller operates the DC-DC converter in the first mode when the input voltage is less than the threshold voltage, and operates the DC-DC converter otherwise.

A drive system comprises a DC-DC converter that is arranged to receive an input voltage from a battery having a nominal battery voltage. The DC-DC converter has a first mode of operation in which the DC-DC converter generates a regulated output voltage from the input voltage and supplies the regulated output voltage to a load, and a second mode of operation in which the DC-DC converter is by-passed such that the input voltage from the battery is supplied to the load. A controller is arranged to compare the input voltage to a threshold voltage that is less than the nominal battery voltage. The controller operates the DC-DC converter in the first mode when the input voltage is less than the threshold voltage, and operates the DC-DC converter otherwise.

A power tool is provided including a brushless direct-current (BLDC) electric motor having a stator and a rotor. The power tool includes power switches including high-side switches and low-side switches disposed on a direct-current (DC) bus line between a power supply and the electric motor, and a controller configured to electronically brake the motor by simultaneously closing the high-side switches or the low-side switches to electrically short the stator windings. In an embodiment, the controller is configured to monitor a voltage of the DC bus line, and if the voltage of the DC bus line is lower than a voltage threshold, execute electronic braking by toggling between closing the high-side switches and closing the low-side switches over braking cycles, and if the voltage of the DC bus line is greater than the voltage threshold, execute braking by closing only the high-side switches or the low-side switches over the braking cycles.

A dual-rotor in-wheel motor based on an axial magnetic field and a control method thereof are provided. The dual-rotor in-wheel motor includes an axle and a hub. The axle is fixedly connected to a frame. The hub relatively rotates around the axle. A disc-shaped intermediate stator is fixedly connected on the axle. A left coil assembly and a right coil assembly are fixedly mounted on two sides of the intermediate stator, respectively. A left rotor and a right rotor are respectively arranged on the two sides of the intermediate stator. The left coil assembly drives the left rotor to rotate, and the right coil assembly drives the right rotor to rotate. A left clutch is arranged between the left rotor and the hub, and a right clutch and a speed reduction mechanism are arranged between the right rotor and the hub.