Patent application number | Description | Published |
20100280714 | MOTOR CONTROLLER AND ELECTRIC POWER STEERING APPARATUS - An angle calculator determines an angle of a rotor. An angular speed calculator determines an angular speed of the rotor. A command current calculator determines a command current defined on a dq-axis. An open loop controller determines a command voltage defined on the dq-axis in accordance with a circuit equation of a motor, based on the command current and the angular speed. A dq-axis/three-phase converter converts the command voltage into a three-phase command voltage. A resistance calculator and a Φ-value calculator respectively determines circuit resistance including armature winding resistance and a number of armature winding linkages which are included in the circuit equation of the motor, based on temperature of the motor detected by a temperature sensor and with reference to a table or the like which is stored in advance. | 11-04-2010 |
20100294586 | ELECTRIC POWER STEERING APPARATUS - When stopping operation of an electric power steering apparatus, a motor relay is kept in an on-state even after a power supply relay is in an off-state. A drive control portion sets a target value of a d-axis current to a value other than zero and sets a target value of a q-axis current to zero, and performs a processing same as that at the time of rotating a motor. MOS-FETs contained in a motor driving circuit are controlled such that each of driving currents of the two phases or more is not zero and the brushless motor does not rotate even supplied with these driving currents. Electric charge accumulated in a capacitor is discharged via the MOS-FETs each in an on-state, a motor relay and the windings of the brushless motor. The electric charge accumulated in the capacitor may be discharged via the excitation coil of the motor relay. | 11-25-2010 |
20110018487 | MOTOR CONTROL DEVICE - A motor control device of the present invention includes: target electric current value setting units ( | 01-27-2011 |
20110022271 | MOTOR CONTROLLER AND ELECTRONIC POWER STEERING APPARATUS - An angle calculator detects a rotation angle θa of a rotor. A three-phase/d-q axis converter outputs detected current id, iq on d-q coordinate axes by making a conversion, based on a corrected detection angle θc obtained by adding or subtracting an amount of detection deviation from a time point of current detection to or from the detection angle θa. A command current calculator calculates command current id*, iq* on the d-q coordinate axes based on a steering torque T and a speed S. A feedback controller calculates command voltages vd, vq on the d-q coordinate axes based on the command current id*, iq* and the detected current id, iq. A d-q axis/three-phase converter converts the command voltages vd, vq into three-phase command voltages, based on a corrected detection angle θb obtained by adding an amount of detection deviation from a time point when a motor is driven to the detection angle θa. The deviation can be eliminated by the command voltages, and the motor can be driven with high precision. | 01-27-2011 |
20110025238 | MOTOR CONTROLLER AND ELECTRONIC POWER STEERING APPARATUS - A command current setting portion has a target value corrector that calculates d-axis and q-axis current command values idc, iqc that are to be supplied to an open-loop controller, based on d-axis and q-axis current target values id*, iq*. When d-axis and q-axis voltage target value vd*, vq* calculated from the d-axis and q-axis current target values id*, iq* by the motor circuit equations exceed a voltage limit, this target value corrector | 02-03-2011 |
20110043144 | MOTOR CONTROLLER AND ELECTRIC POWER STEERING SYSTEM - In a motor controller, a current detection unit detects an electric current flowing through a brushless motor. An open loop control unit determines a command value indicating a level of a command voltage in accordance with a motor circuit equation, based on a command current value indicating an amount of electric current to be supplied to the brushless motor and an angular velocity of a rotor in the brushless motor. A correction unit calculates a correction value based on a difference between the command current value and a current value detected by the current detection unit when the electric current is detected by the current detection unit and corrects the command value according to the correction value, and corrects the command value according to the correction value even when an electric current is not detected by the current detection unit. | 02-24-2011 |
20110214934 | MOTOR CONTROL DEVICE AND ELECTRIC POWER STEERING DEVICE - In a motor control device, a control calculation unit obtains a phase voltage instruction value. A current detecting unit detects an electric current which flows into the brushless motor. A rotational position detecting unit detects the rotational position of a rotor in the brushless motor. A correction unit corrects the phase voltage instruction value based on the detection results of the current detecting unit and the rotational position detecting unit so that a dependency of a ratio on an electric angle shown by a secondary harmonic component of the ratio concerning the electric angle of the brushless motor. The ratio is a ratio of a q-axis or d-axis component of the electric current, which flows into the brushless motor, to a q-axis or d-axis instruction value. A driving unit drives the brushless motor based on the phase voltage instruction value after the correction by the correction unit. | 09-08-2011 |
Patent application number | Description | Published |
20100008686 | METHOD OF DETECTING POSITION OF TONER PATTERN, OPTICAL SENSOR, AND IMAGE FORMING APPARATUS - A light-emitting unit includes M (M≧3) number of light-emitting elements. A light-receiving unit includes N (N≧3) number of light-receiving elements that receive a reflected light from at least one of a supporting member and a toner pattern. The toner pattern is formed on a surface of the supporting member. A detection light is emitted onto the supporting member from the light-emitting unit. A reflected light reflected from at least one of the supporting member and the toner pattern is received by the light-receiving unit. A position of the toner pattern on the supporting member is detected based on outputs of the light-receiving elements. | 01-14-2010 |
20110043810 | REFLECTIVE OPTICAL SENSOR AND IMAGE FORMING APPARATUS - A reflective optical sensor detects a position and/or a toner density of the toner pattern. The reflective optical sensor includes an illuminating system that has at least three light-emitting units, a light-receiving system that has at least three light-receiving units and receives light output from the illuminating system and reflected by the toner pattern, and an illuminating optical system that includes at least three illuminating condenser lenses individually corresponding to the at least three light-emitting units and that guides the light output from the illuminating system to the toner pattern. The at least three light-emitting units and the at least three light-receiving units are both arranged in equal distance with respect to one direction. Optical axes of the at least three illuminating condenser lenses are off-center in parallel to an axis passing through a center of and perpendicular to the corresponding light-emitting unit. | 02-24-2011 |
20110134500 | OPTICAL SCANNING DEVICE AND IMAGE FORMING APPARATUS - An optical scanning device includes a coupling optical system, a light source including a plurality of light emitting units for emitting light beams, and a deflector including a deflecting surface for deflecting the light beams. The coupling optical system is arranged on an optical path between the light source and the deflector so that the light beams enter the deflector at an angle with respect to a normal direction of the deflecting surface in a sub-scanning direction. The light emitting units are arranged two-dimensionally, and a distance between two light emitting units at opposite ends in a main scanning direction is smaller than a distance between two light emitting units at opposite ends in the sub-scanning direction. | 06-09-2011 |
20110228368 | OPTICAL SCANNING DEVICE, OPTICAL WRITING DEVICE, AND IMAGE FORMING APPARATUS - An optical scanning device includes a first optical system for guiding light beams emitted from a plurality of light emitting units to an optical deflector, and a second optical system for focusing the light beams to optically scan a surface to be scanned. At least one of the first optical system and the second optical system includes a resin lens having a diffractive surface. The diffractive surface includes a diffractive portion and a refractive portion. A power of the diffractive portion and a power of the refractive portion cancel each other. | 09-22-2011 |
20140044460 | MOVING-MEMBER DETECTING DEVICE AND IMAGE FORMING APPARATUS - A moving-member detecting device includes an image acquiring unit and a speed calculating unit. The image acquiring unit includes a light source configured to emit a light beam to a detecting position of a moving member; an area sensor configured to acquire image data of a one- or two-dimensional image; and an area-sensor control unit configured to acquire the image data. The image acquiring unit is configured to acquire pieces of image data of the moving member at first and second positions, respectively, in a moving direction of the moving member so as to acquire the piece of position image data for the second position when the moving member is at the second position after acquiring the piece of image data for the first position. The speed calculating unit is configured to calculate a moving speed of the moving member from the pieces of image data. | 02-13-2014 |
20150092994 | ELIGIBLE OPERATOR DETERMINATION DEVICE AND ELIGIBLE OPERATOR DETERMINATION METHOD - An eligible operator determination device includes a three-dimensional light measurement unit configured to measure three-dimensional coordinates of respective parts in a visual field including a posture of a monitor target operating a device; a motion recognition unit configured to recognize a predetermined ineligible motion from a measurement result obtained by the three-dimensional light measurement unit; and an ineligibility coping unit configured to execute a predetermined process according to the predetermined ineligible motion, when the predetermined ineligible motion is recognized by the motion recognition unit. | 04-02-2015 |
Patent application number | Description | Published |
20080290826 | Motor Controller - A motor controller stores values corresponding to predetermined equivalent resistance which corresponds to power loss generated by switching on and off switching elements. Voltage command values are determined by adding voltage drop values determined from values corresponding to the equivalent resistance and values of current flowing in the switching elements to target applied voltage values corresponding to current command values which correspond to target output of a motor. The switching elements arranged in a power supply line to the motor are switched on and off by control signals generated according to the voltage command values. | 11-27-2008 |
20090079373 | MOTOR CONTROLLER AND ELECTRIC POWER STEERING SYSTEM - A current sensor of a motor controller detects the current applied to a motor drive circuit and thus a phase where a failure cannot be detected would occur without taking any measures. However, an abnormal current monitor section contained in a microcomputer receives a voltage signal of an average value of the currents detected in the current sensor by allowing a signal to pass through a first LPF having a cutoff frequency sufficiently lower than the frequency of a PWM signal. Therefore, whether or not the value is within a predetermined normal range is checked, whereby whether or not some failure containing a failure of the current sensor occurs can be easily determined about every phase. | 03-26-2009 |
20090256503 | MOTOR CONTROL APPARATUS AND ELECTRIC POWER STEERING SYSTEM - If the magnitude of a command voltage vector is greater than a predetermined voltage value indicated by a voltage limit circle, the magnitude of a voltage vector, which corresponds to a q-axis current and which forms the command voltage vector, is adjusted so that the magnitude of the command voltage vector is equal to or less than the predetermined voltage value. Then a q-axis current estimated value is obtained based on i) the ratio of the magnitude of the voltage vector from the q-axis current after adjustment to the magnitude of the voltage vector from the q-axis current before adjustment, and ii) a q-axis current command value. | 10-15-2009 |
20100045217 | Motor control apparatus and electric power steering apparatus - An angle calculation portion of a motor control apparatus determines an angle θ of a rotor, and an angular velocity calculation portion determines an angular velocity ωe of the rotor. A command current calculation portion determines command currents id* and iq* on dq axes, based on a steering torque T and a vehicle speed S. An open-loop control portion determines command voltages vd and vq on the dq axes based on the command currents id* and iq* and the angular velocity ωe, according to circuit equations of a motor. A dq-axis/three-phase conversion portion converts the command voltages vd and vq to command voltages of three phases. A three-phase voltage correction portion corrects the command voltage so that an actual time average value of a voltage applied to each phase is equal to a time average value of a voltage that is to be applied to the phase if the voltage is not decreased, in order to compensate for a decrease in the applied voltage. By performing the correction, it is possible to eliminate or suppress a decrease in control accuracy due to a wiring resistance and the like. | 02-25-2010 |
20120080259 | MOTOR CONTROL DEVICE AND ELECTRIC POWER STEERING APPARATUS - An angular velocity estimate (ωe) used in motor control of an electric power steering is obtained as follows. In a first state period during which the motor substantially stops its rotation, a resistance calculation unit calculates a motor resistance value (Rc) on the basis of a detected value (Vm) of motor voltage and a detected value (Im) of motor current. An average calculation unit obtains an average value (Rav) of the calculated resistance values (Rc) in a retained period. A current-resistance characteristic that associates motor current with motor resistance is held in a characteristic holding unit, and a characteristic updating unit updates the current-resistance characteristic on the basis of the average value (Rav). An estimate calculation unit calculates the angular velocity estimate (ωe) on the basis of the detected value (Vm) of motor voltage, the detected value (Im) of motor current and a motor resistance value (Rm) obtained from the current-resistance characteristic. | 04-05-2012 |
20120139532 | ROTATION ANGLE DETECTION DEVICE - An output signal V | 06-07-2012 |
20120143563 | ROTATION ANGLE DETECTION DEVICE - A first rotation angle computing unit computes a first rotation angle corresponding to a rotation angle of a rotor based on an output signal of a first magnetic sensor and an output signal of a second magnetic sensor. A second rotation angle computing unit computes a second rotation angle corresponding to the rotation angle of the rotor based on the output signal of the second magnetic sensor and an output signal of a third magnetic sensor. A rotation angle selection unit determines a final rotation angle using the first rotation angle and the second rotation angle. | 06-07-2012 |
20120158340 | ROTATION ANGLE DETECTION DEVICE - A rotation angle calculation unit includes a first rotation angle calculation portion, a second rotation angle calculation portion, a third rotation angle calculation portion, an abnormality monitoring portion, and a final rotation angle calculation portion. The abnormality monitoring portion determines, based on a first output signal, a second output signal, and a third output signal, whether the first to third output signals are each normal or abnormal. The final rotation angle calculation portion calculates a final rotation angle based on the final determination result obtained by the abnormality monitoring portion and the first to third rotation angles calculated by the first to third rotation angle calculation portions, respectively. | 06-21-2012 |
20120158341 | ROTATION ANGLE DETECTION DEVICE - A rotation angle calculation unit calculates a zero-crossing time point when a zero-crossing is detected for an output signal V | 06-21-2012 |
20120182008 | ROTATION ANGLE DETECTING DEVICE - Three magnetic sensors are arranged around a rotor at predetermined angular intervals about the rotation axis of the rotor. Sinusoidal signals that have a phase difference of a predetermined degree of 45° are output from the respective magnetic sensors. A rotation angle computing device detects a magnetic pole transition in a first output signal as follows. Specifically, the rotation angle computing device detects a magnetic pole transition in the first output signal based on a value having a larger absolute value between a current value of the second sinusoidal signal and a current value of the third sinusoidal signal, an immediately preceding value of the first sinusoidal signal and a current value of the first sinusoidal signal. | 07-19-2012 |
20120182009 | ROTATION ANGLE DETECTING DEVICE - Three magnetic sensors are arranged around a rotor at predetermined angular intervals about the rotation axis of the rotor. Sinusoidal signals having a phase difference of 120° are output from the magnetic sensors. A rotation angle computing device detects a magnetic pole transition in a first output signal as follows. The rotation angle computing device detects a magnetic pole transition in the first output signal based on a current value of one of the second and third sinusoidal signals, an absolute value of a difference between an immediately preceding value and the current value of the one of the second and third sinusoidal signals being larger than an absolute value of a difference between an immediately preceding value and the current value of the other of the second and third sinusoidal signals, an immediately preceding value of the first sinusoidal signal and a current value of the first sinusoidal signal. | 07-19-2012 |
20120227514 | ROTATION ANGLE DETECTION DEVICE AND TORQUE DETECTION DEVICE - A rotor includes a cylindrical magnet having a plurality of magnetic pole pairs. There are two types of the magnitude of magnetic force in the magnetic pole pairs, that is, a relatively large first magnetic force and a second magnetic force that is smaller than the first magnetic force. Three magnetic sensors are arranged around the rotor. A rotation angle computing device detects the peak values of output signals of the respective magnetic sensors. Then, the rotation angle computing device identifies the magnetic pole pair, sensed by the first magnetic sensor, based on a combination of the local maximum values of the three output signals. | 09-13-2012 |
20120229126 | ROTATION ANGLE DETECTION DEVICE - When the zero-crossing of one of the output signals of magnetic sensors has been detected, a rotation angle computing device identifies a magnetic pole sensed by the first magnetic sensor based on the other two output signals. Subsequently, the rotation angle computing device identifies the magnetic pole sensed by the second magnetic sensor and the magnetic pole sensed by the third magnetic sensor based on the magnetic pole sensed by the first magnetic sensor. After that, the rotation angle computing device corrects the amplitude of the output signal of each magnetic sensor based on the identified magnetic poles respectively sensed by the magnetic sensors. Then, the rotation angle computing device computes the electric angle θe of the rotor based on the corrected output signals. | 09-13-2012 |
20120232839 | ROTATION ANGLE DETECTION APPARATUS - A first third harmonic component removing portion calculates an approximate value (sin θ) | 09-13-2012 |
20120319680 | ROTATION ANGLE DETECTION DEVICE - Upon detecting a peak value from output signals of one of either a first or a second magnetic sensor, an rotation angle computation device identifies, on basis of an amplitude compensation table corresponding to the one magnetic sensor for which the peak value was detected, a pole number of a magnetic pole sensed by the magnetic sensor. Then, based on the identified pole number and a magnetic pole identification table, a pole number of a magnetic pole sensed by the other magnetic sensor is identified. The pole numbers of the magnetic poles sensed by the respective magnetic sensors are thus identified, and the rotation angle computation device compensates the output signals of the respective magnetic sensors using amplitude compensation gains corresponding to the sensed magnetic poles (magnetic pole pair). | 12-20-2012 |
20130035896 | ROTATION ANGLE DETECTION DEVICE - Angular widths of respective magnetic poles of a detection rotor are stored and divisions are set for respective magnetic pole pairs. Based on output signals from first and second magnetic sensors, a rotation angle computation unit computes first and second rotation angles that are rotation angles within the corresponding division. Based on the angular widths, the rotation angle computation unit identifies the magnetic pole sensed by the first magnetic sensor and computes a first absolute rotation angle using the first rotation angle. Based on the identified magnetic pole and the second rotation angle, the rotation angle computation unit computes a second absolute rotation angle. The rotation angle of the detection rotor is computed based on the first and second absolute angles. | 02-07-2013 |
20130197761 | MOTOR CONTROL DEVICE AND ELECTRIC POWER STEERING DEVICE - A motor control device for driving a brushless motor includes a current detecting unit which detects respective phase currents which flow into the brushless motor; a control calculation unit which calculates instruction values showing respective phase voltages to be applied to the brushless motor, and outputs the instruction values as phase voltage instruction values; a phase resistance calculation unit which calculates respective phase resistance values based on detection values of the respective phase currents detected by the current detecting unit, and the instruction values of the respective phase voltages applied to the brushless motor at the time of the detection of the detection values; a correction unit which corrects the phase voltage instruction values according to the respective phase resistance values calculated by the phase resistance calculation unit; and a driving unit which drives the brushless motor based on the phase voltage instruction values after correction by the correction unit. | 08-01-2013 |
20130312540 | TORQUE DETECTING APPARATUS - A torque detecting apparatus detects a torque applied to a first shaft, based on a relative rotational displacement between the first shaft and a second shaft caused by torsion in a coupling shaft which couples the first shaft and the second shaft. The torque detecting apparatus includes: first and second magnets which are coupled to the first shaft and the second shaft so as to rotate together with the first shaft and second shaft, respectively; and a plurality of magnetic sensors which are disposed between the first magnet and the second magnet and which detect a rotational angle of the first shaft and a rotational angle of the second shaft. | 11-28-2013 |
20140116792 | MATERIAL HANDLING AND STAIR CLIMBING VEHICLE - In a material handling and stair climbing vehicle, when the vehicle is shifted from a state where the wheels with two axles are grounded on a travelling surface to a standing state achieved by the wheels with one axle, a main body portion is turned around support shafts with respect to supporting portions in the two-axle wheel grounded state. Then, an inertial force around the support shafts is generated by reducing the speed of turning of the main body portion with respect to the supporting portions. Then, the vehicle is shifted to the standing state achieved by the wheels with one axle by turning the supporting portions around the axles of the wheels with one axle, which are grounded on the travelling surface, by the inertial force. | 05-01-2014 |