摘要:
A rotation detector includes a motor, a current detector and a hardware processor. The motor includes coils of two or more phases and a rotor. The current detector detects currents flowing in coils of at least two phases among the coils of two or more phases. The hardware processor estimates an initial position of the rotor based on current values of the currents detected by the current detector to start the motor, controls an energization pattern on the phases to rotate and start the motor based on the estimated initial position, and determines whether the rotor stops or is rotating before completing the estimation of the initial position.
摘要:
In a motor control device, when estimating an initial position of a magnetic pole of a rotor of a motor, a drive circuit continuously or intermittently applies a voltage to a stator winding at each of a plurality of energization angles while sequentially changing the energization angles, and at a voltage value and for an energization time period, the voltage value and the energization time period being set such that the rotor does not rotate. An initial position estimation unit calculates an estimated initial position of the magnetic pole of the rotor based on a phase angle of a trigonometric function curve that approximates a change of a γ-axis current Iγ with respect to each of the energization angles. The trigonometric function curve has a cycle equal to one electrical cycle of the motor.
摘要:
In a motor control device that controls a sensorless-type motor, a controller estimates an initial magnetic pole position of a rotor of a motor by an inductive sensing scheme while sequentially setting a plurality of energization angles. At each of the set energization angles, the controller converts peak values of currents flowing through a plurality of phases of a stator winding into a first current component having an electrical angle that is equal to a corresponding one of the set energization angles and a second current component that is different in electrical angle by 90 degrees from the first current component, to correct the first current component based on the second current component. The controller estimates the initial magnetic pole position of the rotor based on the corrected first current component that is obtained at each of the set energization angles.
摘要:
A method for controlling a permanent magnet synchronous motor having a rotor using a permanent magnet, the rotor rotating by a rotating magnetic field caused by a current flowing through an armature is provided. The method includes: presuming, based on a target speed and an estimated speed that is an estimated value of a rotational speed of the rotor, whether or not a step-out occurs; correcting, when it is presumed that a step-out occurs, an estimated angle that is an estimated value of a position of magnetic poles of the rotor; and controlling, based on a post-correction estimated angle that is the estimated angle after the correction, a current flowing through the armature to cause the rotating magnetic field rotating at the target speed.
摘要:
A sheet feeder picking up and transporting sheets includes a transport unit transporting sheets along a sheet transport path one by one, a gap occurrence detection unit detecting, within a predetermined section of the sheet transport path, occurrence of a gap between sheets, and a controller controlling a timing of the transport of sheets according to a result of the detection. The gap occurrence detection unit includes a first detection unit and a second detection unit. The first detection unit is configured to detect light that is emitted toward the predetermined section, reaches a converging surface thereof across the predetermined section, and converged on a receiving element thereof. The second detection unit is configured to detect light reflected by a sheet passing through the predetermined section. The occurrence of the gap is detected based on outputs from the first detection unit and the second detection unit.
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 control device of a permanent magnet synchronous motor that is a control device of a sensorless-type permanent magnet synchronous motor in which a rotor using a permanent magnet rotates by a rotating magnetic field caused by a current flowing in an armature includes: a driver that applies a voltage to the armature and drives the rotor; an initial position estimator that estimates an initial position which is a magnetic pole position of the rotor that is stopped; and a controller that controls the driver so as to apply a pulse train including a voltage pulse for searching the initial position for each of n angle positions dividing a search range of an electrical angle of 360 degrees to the armature, wherein the pulse train includes a first pulse and a second pulse.
摘要:
An image forming apparatus includes: a photosensitive member rotated in a predetermined direction; a charging unit configured to charge a circumferential surface of the photosensitive member; a developing unit carrying a developer including toner and carriers, and including a developer bearing member configured to apply toner charged in a first polarity to the circumferential surface of the photosensitive member; a first voltage applying unit configured to apply a first voltage of the first polarity to the charging unit; a second voltage applying unit configured to apply a second voltage of the first polarity to the developer bearing member; a first voltage detecting unit configured to detect the first voltage; a second voltage detecting unit configured to detect the second voltage; and a controller, wherein the controller determines whether or not to make a second rate lower than a first rate according to the second voltage at a first timing.
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:
A motor controller includes: a velocity calculation unit for obtaining an angle θ(n), which shows a rotation position, and an angular velocity ω(n) of a rotor at a time point n; a compensation amount calculation unit for calculating a compensation angle Δθ by which the rotor advances from the time point n to a (n+1)th control cycle (a control cycle starting from a time point n+1), based on an angular acceleration a(n) of the rotor, an angular velocity ω(n) of the rotor at the time point n and a time length T of the control cycle; and a PWM inverter for controlling a voltage to be applied to a coil such that a rotating magnetic field based on a rotation position of the rotor advanced by the compensation angle Δθ from the rotation position of the rotor at the time point n is formed in the (n+1)th control cycle.