A rotational stop position of a motor is accurately controlled. A motor driving control device (100) includes a BEMF detection unit (118) for detecting zero-cross of back electromotive force of a motor coil provided in a motor, and a CPU (101) for controlling driving of the motor by a 1-phase energization method and, without a position sensor, performing commutation based on the zero-cross of the back electromotive force detected by the BEMF detection unit (118), controlling driving of the motor based on a rotational speed corresponding to a drive voltage and a load, and performing extension control of a commutation time for each step from a calculated deceleration start step until the rotational speed of the motor decreases to a predetermined rotational speed or less for enabling the motor to stop at a desired stop position when the driving of the motor is stopped.

A rotational stop position of a motor is accurately controlled. A motor driving control device (100) includes a BEMF detection unit (118) for detecting zero-cross of back electromotive force of a motor coil provided in a motor, and a CPU (101) for controlling driving of the motor by a 1-phase energization method and, without a position sensor, performing commutation based on the zero-cross of the back electromotive force detected by the BEMF detection unit (118), controlling driving of the motor based on a rotational speed corresponding to a drive voltage and a load, and performing extension control of a commutation time for each step from a calculated deceleration start step until the rotational speed of the motor decreases to a predetermined rotational speed or less for enabling the motor to stop at a desired stop position when the driving of the motor is stopped.

A valve actuator (10) has a damping circuitry including a capacitive damping circuit (37), which is activated in the event of generator operation of the stepper motor (18). The damping circuitry, together with the motor winding (26), forms a resonance assembly LCR, which has the effect of stabilising and regulating rotational speed. The rotational speed of the stepper motor (18), running in generator operation, is held constant within limits, specifically without the control intervention of control circuitry. Therefore, the damping circuitry can operate even in the currentless state of the control system and is reliable regardless of external current supply. Fast closing is achieved, and excessively long post-running of the motor (18) is reliably prevented.

A method of controlling an actuator comprising an electric motor and an actuator coupled to the electric motor, the method comprising controlling the electric motor to move the actuator in a direction towards an absolute mechanical end stop until a last registered soft reference position has been reached and then to overtravel the last registered soft reference position by a predetermined distance, detecting the load of the actuator, and updating the registered soft reference position on the basis of the detected load.

A method of controlling an actuator comprising an electric motor and an actuator coupled to the electric motor, the method comprising controlling the electric motor to move the actuator in a direction towards an absolute mechanical end stop until a last registered soft reference position has been reached and then to overtravel the last registered soft reference position by a predetermined distance, detecting the load of the actuator, and updating the registered soft reference position on the basis of the detected load.

A lens control device that moves a lens in an optical axis direction comprises a stepping motor that drives the lens, a position detection circuit that detects position of the lens in an optical axis direction, a memory that stores data relating to a relationship between rotational position of the stepping motor and detected position of the position detection circuit, and a controller that designates rotational position of the stepping motor based on target information that is input, determines a virtual target rotational position based on a target position corresponding to detected position of the position detection circuit corresponding to the target information that has been input, and, based on the virtual target rotational position, searches for a rotational position that corresponds to the target position, within a range of given rotational positions of the data.

A lens control device that moves a lens in an optical axis direction comprises a stepping motor that drives the lens, a position detection circuit that detects position of the lens in an optical axis direction, a memory that stores data relating to a relationship between rotational position of the stepping motor and detected position of the position detection circuit, and a controller that designates rotational position of the stepping motor based on target information that is input, determines a virtual target rotational position based on a target position corresponding to detected position of the position detection circuit corresponding to the target information that has been input, and, based on the virtual target rotational position, searches for a rotational position that corresponds to the target position, within a range of given rotational positions of the data.

An automated luminaire and method are provided. The automated luminaire includes a stepper motor, a mechanism moved by the stepper motor, and a control system coupled to the stepper motor. The control system rotates the stepper motor, senses a current passing through a motor winding of the stepper motor, determines from a calculated characteristic of the sensed current that the mechanism has contacted an end stop, and in response, stores data relating to a current position of the stepper motor in a memory of the control system.

A textile machine and associated method are provided for operating the textile machine that includes a plurality of workstations, wherein each workstation includes at least one stepper motor configured to drive an element at the workstation. The method includes measuring a load variable, for example a load angle, of the stepper motor and detecting an approach of the element to an end position based on changes to the load variable.

A driving device for a stepping motor includes a motor driving circuit configured to generate a current waveform representing an electrical angle in synchronization with a mechanical angle of the stepping motor, and excite the stepping motor using the current waveform; a memory configured to store a value of the electrical angle; and a controller configured to: when a power supply to the stepping motor and the motor driving circuit is stopped, store a first value of the electrical angle held by the motor driving circuit in the memory; and when the power supply is resumed, replace a value of the electrical angle of the motor driving circuit with the first value while suppressing a rotational operation of the stepping motor.