Abstract: Disclosed is a system comprising: a plant (P) to be controlled; a controller (C); a first weight function (W1); a second weight function (W2); and a disturbance observer, wherein the first weight function (W1) receives a difference value between a disturbance (w) and an output (uDO) of the disturbance observer as an input value, the second weight function (W2) receives a difference value between the output value of the controller (C) and the output (uDO) of the disturbance observer as an input value, the plant (P) to be controlled receives, as an input value, the sum value of the disturbance (w) and the difference value between the output value of the controller (C) and the output (uDO) of the disturbance observer, and the controller (C) receives an output value of the plant (P) to be controlled as an input value.

Abstract: Disclosed is a system comprising a robust optimal disturbance observer for high-precision position control performed by an electronic device. The system comprises: a plant (P) to be controlled; a controller (C); a first weight function (W1); a second weight function (W2); and a disturbance observer, wherein the first weight function (W1) receives a difference value between a disturbance (w) and an output (uDO) of the disturbance observer as an input value, the second weight function (W2) receives a difference value between the output value of the controller (C) and the output (uDO) of the disturbance observer as an input value, the plant (P) to be controlled receives, as an input value, the sum value of the disturbance (w) and the difference value between the output value of the controller (C) and the output (uDO) of the disturbance observer, and the controller (C) receives an output value of the plant (P) to be controlled as an input value.

Abstract: The camera module includes: a first frame that is formed to surround a lens and fixes the lens; a second frame that is formed to surround the first frame and is apart from the first frame; a third frame that is formed to surround the second frame and is apart from the second frame; a plurality of first piezoelectric actuators that connect the first frame to the second frame; and a plurality of second piezoelectric actuators that connect the second frame to the third frame, wherein the plurality of first piezoelectric actuators are arranged in parallel in a first direction around the lens, and the plurality of second piezoelectric actuators are arranged in parallel in a second direction around the lens.

Abstract: The camera module includes: a first frame that is formed to surround a lens and fixes the lens; a second frame that is formed to surround the first frame and is apart from the first frame; a third frame that is formed to surround the second frame and is apart from the second frame; a plurality of first piezoelectric actuators that connect the first frame to the second frame; and a plurality of second piezoelectric actuators that connect the second frame to the third frame, wherein the plurality of first piezoelectric actuators are arranged in parallel in a first direction around the lens, and the plurality of second piezoelectric actuators are arranged in parallel in a second direction around the lens.

Abstract: A hard disk drive is provided. The hard disk drive comprises a plant configured to drive the hard disk drive, a main controller configured to control the plant, and an additional controller connected in parallel with the main controller. A response function in consideration of the plant and the main controller is referred to as a main response function, and a response function in consideration of the plant and the additional controller is referred to as a first response function. The first response function cancels a function value corresponding to a section of the main response function that is associated with disturbance. The response function of the additional controller may be designed using the first response function. The hard disk drive removes a portion of the main response function to minimize the influence of the disturbance.

Abstract: Provided are a hard disk drive (HDD) assembly and a mobile phone employing the HDD assembly. The HDD assembly includes: a HDD including a base member, a cover member, a spindle motor installed on the base member, at least one data storage disk mounted on the spindle motor, and an actuator pivotably installed on the base member and moving a read/write head to a predetermined position on the disk; a printed circuit board (PCB) disposed beside the HDD and operating the HDD; and a mounting bracket mounted on an electronic device while accommodating the HDD and the PCB, and including a first accommodating space adapted to accommodate the HDD and a second accommodating space disposed beside the first accommodating space and adapted to accommodate the PCB.

Abstract: A method and system are disclosed for compensating disturbance applied to a plant, such as a HDD component, controlled by a state control device having an estimator & controller. The estimator & controller is adapted to generate a first control signal in response to a state signal indicating an estimated state of the plant. A second control signal is generated by applying a transfer function H(s) having defined gain/frequency characteristics to a control signal derived from the first control signal. An overall control signal is generated in response to the second control signal and the control signal derived from the first control signal and applied to the plant.

Abstract: A hard disk drive is provided. The hard disk drive comprises a plant configured to drive the hard disk drive, a main controller configured to control the plant, and an additional controller connected in parallel with the main controller. A response function in consideration of the plant and the main controller is referred to as a main response function, and a response function in consideration of the plant and the additional controller is referred to as a first response function. The first response function cancels a function value corresponding to a section of the main response function that is associated with disturbance. The response function of the additional controller may be designed using the first response function. The hard disk drive removes a portion of the main response function to minimize the influence of the disturbance.

Abstract: Provided are a voice coil motor (VCM) driving method for an HDD, related head unloading apparatus and recording media suitable for implementing the driving method. The method of driving a VCM to park a head on a ramp in the HDD includes; driving the VCM using a first driving voltage until the head moves to a first position; and thereafter driving the VCM using a second driving voltage higher than the first driving voltage during a first time period sufficient cause the head to rise along a first incline of the ramp.

Abstract: A method and apparatus for detecting a free fall of an electronic device. The method includes: sensing a falling acceleration of the electronic device using an acceleration sensor; determining whether the sensed falling acceleration is less than a predetermined threshold; when the sensed falling acceleration is less than the predetermined threshold, determining whether the falling acceleration is a statistical constant, which has a statistical significance, and is maintained for a predetermined time; and when the falling acceleration is a statistical constant and maintained for a predetermined time, determining that the electronic device falls freely. Accordingly, it is possible to exactly detect a free fall of an electronic device, irrespective of an error of the acceleration of gravity generated when a falling acceleration of the electronic device is measured, due to ambient conditions, e.g., a temperature change and a rotation acceleration generated when the electronic device rotates.

Abstract: A servo control device for a disk drive capable of effectively compensating for a low frequency disturbance incoming to the disk drive is provided. The servo control device includes: a state variable estimator calculating a position estimation error based on a control input for controlling motion of a head and a position error signal by using a predetermined state equation; an estimation filter calculating a disturbance estimation value from the position estimation error by using a mathematical relation between a disturbance and the position estimation error; and a subtractor subtracting the disturbance estimation value from the control input.

Abstract: Provided are a voice coil motor (VCM) driving method for an HDD, related head unloading apparatus and recording media suitable for implementing the driving method. The method of driving a VCM to park a head on a ramp in the HDD includes; driving the VCM using a first driving voltage until the head moves to a first position; and thereafter driving the VCM using a second driving voltage higher than the first driving voltage during a first time period sufficient cause the head to rise along a first incline of the ramp.

Abstract: A method and system are disclosed for compensating disturbance applied to a plant, such as a HDD component, controlled by a state control device having an estimator & controller. The estimator & controller is adapted to generate a first control signal in response to a state signal indicating an estimated state of the plant. A second control signal is generated by applying a transfer function H(s) having defined gain/frequency characteristics to a control signal derived from the first control signal. An overall control signal is generated in response to the second control signal and the control signal derived from the first control signal and applied to the plant.

Abstract: A servo control device for a disk drive capable of effectively compensating for a low frequency disturbance incoming to the disk drive is provided. The servo control device includes: a state variable estimator calculating a position estimation error based on a control input for controlling motion of a head and a position error signal by using a predetermined state equation; an estimation filter calculating a disturbance estimation value from the position estimation error by using a mathematical relation between a disturbance and the position estimation error; and a subtractor subtracting the disturbance estimation value from the control input.

Abstract: A method and apparatus for detecting a free fall of an electronic device. The method includes: sensing a falling acceleration of the electronic device using an acceleration sensor; determining whether the sensed falling acceleration is less than a predetermined threshold; when the sensed falling acceleration is less than the predetermined threshold, determining whether the falling acceleration is a statistical constant, which has a statistical significance, and is maintained for a predetermined time; and when the falling acceleration is a statistical constant and maintained for a predetermined time, determining that the electronic device falls freely. Accordingly, it is possible to exactly detect a free fall of an electronic device, irrespective of an error of the acceleration of gravity generated when a falling acceleration of the electronic device is measured, due to ambient conditions, e.g., a temperature change and a rotation acceleration generated when the electronic device rotates.

Abstract: Provided are a hard disk drive (HDD) assembly and a mobile phone employing the HDD assembly. The HDD assembly includes: a HDD including a base member, a cover member, a spindle motor installed on the base member, at least one data storage disk mounted on the spindle motor, and an actuator pivotably installed on the base member and moving a read/write head to a predetermined position on the disk; a printed circuit board (PCB) disposed beside the HDD and operating the HDD; and a mounting bracket mounted on an electronic device while accommodating the HDD and the PCB, and including a first accommodating space adapted to accommodate the HDD and a second accommodating space disposed beside the first accommodating space and adapted to accommodate the PCB.