An angle detecting device includes a rotatably supported magnet, and a magnetic sensor disposed opposite to the magnet. An output of the magnetic sensor is changed based on a magnetic flux change due to a rotation of the magnet. The magnet is disposed such that a distance between the magnetic sensor and the magnet is changed by the rotation of the magnet.

An inverter converts direct-current power to alternating-current power by operations of a plurality of switching elements under a PWM control, and supplies the alternating-current power to an alternating-current electric motor. A feedback control computation unit of an inverter control unit uses current values acquired from current sensors detecting a current flowing to the alternating-current electric motor and a rotation angle of the alternating-current electric motor to perform a control computation in a (N/2) cycle (N is a natural number) of a triangular wave carrier of the PWM control. At the acquisition of the current values detected by the current sensors, an average acquisition unit acquires an average of current values in a carrier half cycle as a period between a peak and a valley of the carrier, or acquires a current value regarded as an average of the current values at an acquirable timing.

An inverter converts direct-current power to alternating-current power by operations of a plurality of switching elements under a PWM control, and supplies the alternating-current power to an alternating-current electric motor. A feedback control computation unit of an inverter control unit uses current values acquired from current sensors detecting a current flowing to the alternating-current electric motor and a rotation angle of the alternating-current electric motor to perform a control computation in a (N/2) cycle (N is a natural number) of a triangular wave carrier of the PWM control. At the acquisition of the current values detected by the current sensors, an average acquisition unit acquires an average of current values in a carrier half cycle as a period between a peak and a valley of the carrier, or acquires a current value regarded as an average of the current values at an acquirable timing.

A motor controller circuit having a rotational speed locking mechanism is provided. Each time when a motor commutates, a first signal generating circuit resets a first waveform signal and a second signal generating circuit resets a second waveform signal. An output signal generating circuit outputs a waveform output signal according to the first waveform signal and the second waveform signal. A motor controller circuit outputs an on-time signal according to the waveform output signal. A motor driving circuit outputs a driving signal to the motor to drive the motor to rotate according to the on-time signal.

A motor controller circuit having a rotational speed locking mechanism is provided. Each time when a motor commutates, a first signal generating circuit resets a first waveform signal and a second signal generating circuit resets a second waveform signal. An output signal generating circuit outputs a waveform output signal according to the first waveform signal and the second waveform signal. A motor controller circuit outputs an on-time signal according to the waveform output signal. A motor driving circuit outputs a driving signal to the motor to drive the motor to rotate according to the on-time signal.

Rotation mechanisms for rotating a payload in two, first and second degrees of freedom (DOF), comprising a static base, a first rotation arm coupled mechanically to the static base through a first rotation joint and used for rotating the payload relative to the static base around a first rotation axis that passes through the first rotation joint, a second rotation arm coupled mechanically to the static base through a second rotation joint and used for rotating the payload relative to the static base around a second rotation axis that passes through the second rotation joint, and a follower member rigidly coupled to the payload and arranged to keep a constant distance from the second rotation arm, wherein the rotation of the first arm rotates the payload around the first DOF and the rotation of the second arm rotate the payload around the second DOF.

A method for controlling a gimbal includes detecting a motion of the gimbal, determining whether a received control signal indicates that the motion of the gimbal corresponds to a user-intended motion, controlling the gimbal to move along a moving direction of the motion in response to determining that the received control signal indicates the motion of the gimbal corresponds to the user-intended motion, and controlling the gimbal to move along an opposite direction to the moving direction of the motion in response to determining that the received control signal does not indicate the motion of the gimbal corresponds to the user-intended motion.

Implementations are described herein for offline computation and caching of precalculated joint trajectories. In various implementations, an instruction may be obtained to move an end effector of a robot between start and target positions. A first type of trajectory planning may be performed in real time or online to calculate a first joint trajectory of the robot that moves the end effector from the start to target position. The robot may then implement the first joint trajectory. A second type of trajectory planning may be performed offline, e.g., during downtime of the robot, to precalculate a second joint trajectory of the robot to move the end effector from the start to target position. The second type of trajectory planning may require more resources than were required by the first type of trajectory planning. Data indicative of the precalculated second joint trajectory of the robot may be stored for future use.

Implementations are described herein for offline computation and caching of precalculated joint trajectories. In various implementations, an instruction may be obtained to move an end effector of a robot between start and target positions. A first type of trajectory planning may be performed in real time or online to calculate a first joint trajectory of the robot that moves the end effector from the start to target position. The robot may then implement the first joint trajectory. A second type of trajectory planning may be performed offline, e.g., during downtime of the robot, to precalculate a second joint trajectory of the robot to move the end effector from the start to target position. The second type of trajectory planning may require more resources than were required by the first type of trajectory planning. Data indicative of the precalculated second joint trajectory of the robot may be stored for future use.

A motor apparatus is provided. The motor apparatus includes a motor having a rotor and a stator, an inverter used to covert an input voltage into a three-phase alternating current (AC) voltage and provide the three-phase AC voltage to the motor, an inverter controller used to control the inverter, and a rotation angle sensor. The rotation angle sensor is fixed to the motor and is used to detect a rotation angle of the motor. The inverter controller includes a calculator. The calculator calculates an offset angle of an installation position of the rotation angle sensor according to a difference between a measured value and a theoretical value of a voltage phase of the motor.