摘要:
In a motor control device in one embodiment, an initial position estimation unit estimates an initial position of a magnetic pole of a rotor of a motor in an inductive sensing scheme. At each of energization angles, the initial position estimation unit multiplies a γ-axis current component Iγ corresponding to a peak value of a current flowing through a stator winding by each of a cosine value and a sine value of a correction angle obtained by correcting each of the energization angles. The initial position estimation unit estimates the initial position of the magnetic pole of the rotor based on a ratio between an integrated value of a multiplication result about the cosine value and an integrated value of a multiplication result about the sine value.
摘要:
A device for detecting a travel distance of a sheet is provided. The device includes a light source for irradiating the sheet surface; an imaging sensor for capturing an image of a pattern of the sheet surface by light reflected from the sheet; a discrete Fourier transformation portion for performing discrete Fourier transformation on two patterns obtained by image capturing at a time interval by the imaging sensor; a high wave number component removal portion for using a threshold determined based on a cycle of concave-convex of the sheet surface to remove a high wave number component from the two patterns having been subjected to the discrete Fourier transformation; and a travel distance calculation portion for determining a travel distance of the sheet based on a phase relationship between the two patterns from which the high wave number component removal portion has removed the high wave number component.
摘要:
A control circuit of a motor control device estimates an initial magnetic pole position of a rotor using an inductive sensing scheme. When estimating the initial magnetic pole position, a drive circuit applies a voltage to a stator winding at each of L electrical angles (L≥5) while changing the L electrical angles. An absolute value of an electrical angle difference of the voltage applied to the stator winding between an i-th time (2≤i≤L) and an i−1st time is 180−360/L degrees or more and 180+360/L degrees or less. An absolute value of an electrical angle difference of the voltage applied to the stator winding between a 1st time for initial position estimation and a last time before starting initial position estimation is 180−360/L degrees or more and 180+360/L degrees or less.
摘要:
A photographing system includes a photographing device configured to photograph a surface; a detector configured to detect a change in a position of an object in a space between the surface and the photographing device; and an obtaining portion configured to obtain an image of an area of the surface by the photographing device when the detector detects the change, the area being not viewed by the photographing device before the change due to interruption of the object and being viewed by the photographing device after the change.
摘要:
An image processing apparatus includes: a transport roller for transporting a sheet subjected to image processing; a motor that drives the transport roller to rotate; and a speed reduction unit that performs a speed reduction control on the motor to temporarily stop the sheet, the speed reduction control being performed in a manner that a stopping time and a stopping distance each satisfy a corresponding target range, wherein the speed reduction control includes: a first control that is a control of reducing a rotation speed of the motor to a reference speed through at least two operations from among a braking operation, a powering operation, and a free running operation; and a second control that is a control of, after a rotation amount of the motor from the start of the speed reduction control reaches a reference value, continuously performing the braking operation until the stop of the motor.
摘要:
An image display and photographing system includes a display device configured to display a target image on a surface; a photographing device configured to photograph the surface; a first detector configured to detect that an object moves away from a space between the surface and the photographing device; a second detector configured to detect that, after the first detector detects that the object moves away from the space, the surface is touched at a predetermined position; a third detector configured to detect that, after the second detector detects that the surface is touched at the predetermined position, the object moves away from the space; and a photographing control portion configured to control, after the third detector detects that the object moves away from the space, the photographing device to photograph the surface.
摘要:
A movement amount detecting device performs discrete Fourier transform onto N-th image data and N+1-th image data, thereby generating N-th wave number space data and N+1 -th wave number space data. The movement amount detecting device obtains a target speed of a sheet, and determines a cutoff value based on the obtained target speed and an exposure time in an image sensor. The movement amount detecting device calculates an amount of movement of the sheet based on a phase difference between the N-th wave number space data and the N+1-th wave number space data in a wave number component smaller than the cutoff value.
摘要:
An emission unit of a displacement detector emits laser light to a range in a space in which a target moves. A detection unit detects a distribution of amounts of light reflected from a capture region in the predefined range. Based on a shift of speckle pattern indicated by a difference between the distributions of amounts of reflected light that the detection unit detects at different times, a calculation unit calculates a displacement of the target. A correction unit measures a speckle contrast from the distribution of amounts of reflected light, and based on an error between the measured value and a reference value, corrects the amount of laser light. The reference value is set to the value of a speckle contrast in a case in which the amounts of reflected light fall within the detectable range of the detection unit.
摘要:
An image forming apparatus includes: a conveyance roller configured to convey recording sheets; a brush motor configured to drive the conveyance roller to rotate; and a control unit configured to control a rotational speed of the brush motor, wherein while the conveyance roller conveys a recording sheet, (i) the control unit applies voltage to an outer circumferential surface of a commutator of the brush motor to drive the brush motor to rotate by a predetermined rotation amount, so as to perform a cleaning operation to remove a film deposited on the outer circumferential surface, and (ii) the control unit reduces the rotational speed of the brush motor while not performing the cleaning operation, so as to correct a conveyance distance of the recording sheet.
摘要:
An image forming device including an optical sensor, an ultrasound sensor, and a conveyance guide. The optical sensor and the ultrasound sensor are disposed alongside a conveyance path of a sheet and are used to determine sheet type. The conveyance guide guides the sheet along the conveyance path. The conveyance guide is structured such that, on the conveyance path between the optical sensor and the ultrasound sensor, the sheet is in contact with the conveyance guide while a portion of the sheet is in a light irradiation range of the optical sensor and a different portion of the sheet is in an ultrasound irradiation range of the ultrasound sensor.