Patent application number | Description | Published |
20090134834 | Motor control device - A motor control device includes: a motor-current detection unit; a rotational-angular-speed calculation unit for calculating a rotational angular speed of a motor; a rotational-angle-change-amount calculation unit for multiplying the rotational angular speed by a predetermined time so as to calculate a motor-rotational-angle change amount within a predetermined time; a basic-drive-value calculation unit for calculating a basic drive value for driving the motor; a correction-value calculation unit for calculating a correction value for correcting the basic drive value based on the motor current and the motor-rotational-angle change amount; a correction unit for evaluating the motor drive value by correcting the basic drive value by the correction value; and a drive unit for driving the motor by using the motor drive value evaluated by the correction unit. | 05-28-2009 |
20090190903 | MOTOR CONTROLLER AND VEHICULAR STEERING SYSTEM USING SAID MOTOR CONTROLLER - A low speed region position estimating portion is designed to be suitable for when the motor is operating in a low speed region, and estimates a low speed estimated rotational position θ̂ | 07-30-2009 |
20100094505 | Vehicle steering apparatus - A motor is driven based on an axis current value in a rotating coordinate system that rotates in accordance with a control angle that is a rotational angle used in a control. The control angle is calculated by adding an addition angle to an immediately preceding value of the control angle in each predetermined calculation cycle. A command steering torque is set based on a predetermined steering angle-torque characteristic. The addition angle is calculated based on the deviation of a detected steering torque from a command steering torque. The addition angle based on the deviation is changed when a predetermined condition is satisfied. | 04-15-2010 |
20100235049 | Motor control unit and motor control unit for vehicle steering apparatus - A motor control unit controls a motor including a rotor and a stator facing the rotor. A current drive unit drives the motor at an axis current value of a rotating coordinate system that rotates in accordance with a control angle that is a rotational angle used in a control. A control angle calculation unit obtains, at every predetermined calculation cycle, a present value of the control angle by adding an addition angle to an immediately preceding value of the control angle. A torque detection unit detects a torque other than a motor torque and applied to a drive target driven by the motor. A command torque setting unit sets a command torque to be applied to the drive target. An addition angle calculation unit calculates the addition angle to be added to the control angle through a proportional-integral control based on a torque deviation of the torque detected by the torque detection unit from the command torque set by the command torque setting unit. | 09-16-2010 |
20100235051 | MOTOR CONTROL UNIT AND MOTOR CONTROL UNIT FOR VEHICLE STEERING APPARATUS - A motor control unit controls a motor including a rotor and a stator facing the rotor. A current drive unit drives the motor at an axis current value of a rotating coordinate system that rotates in accordance with a control angle that is a rotational angle used in a control. An addition angle calculation unit calculates an addition angle to be added to the control angle. A control angle calculation unit obtains, at every predetermined calculation cycle, a present value of the control angle by adding the addition angle that is calculated by the addition angle calculation unit to an immediately preceding value of the control angle. A torque detection unit detects a torque that is other than a motor torque and that is applied to a drive target driven by the motor. A command torque setting unit sets a command torque to be applied to the drive target. An addition angle correction unit compares the command torque set by the command torque setting unit with the detected torque detected by the torque detection unit, and corrects the addition angle based on a comparison result. | 09-16-2010 |
20110001441 | Motor Control Unit and Vehicle Steering Apparatus - A motor control unit controls a motor including a rotor and a stator facing the rotor. A current drive unit drives the motor at an axis current value of a rotating coordinate system that rotates in accordance with a control angle that is a rotational angle used in a control. An addition angle calculation unit calculates an addition angle to be added to the control angle. A control angle calculation unit obtains, at every predetermined calculation cycle, a present value of the control angle by adding the addition angle that is calculated by the addition angle calculation unit to an immediately preceding value of the control angle. An angular speed calculation unit calculates an angular speed of the rotor. An addition angle correction unit corrects the addition angle based on the angular speed calculated by the angular speed calculation unit. A filtering unit filters the angular speed calculated by the angular speed calculation unit. | 01-06-2011 |
20110098888 | MOTOR CONTROL DEVICE AND VEHICLE-STEERING DEVICE COMPRISING SAME - A motor controller controls a motor including a rotor and a stator opposed to the rotor. The motor controller includes an electric current driving unit which drives the motor with an axis electric current value defined in a rotating coordinate system defined with respect to a control angle that is a rotation angle for control, a control angle computing unit which computes a current value of the control angle by adding an addition angle to a previous value of the control angle in each predetermined computing cycle, and an addition angle computing unit which computes the addition angle according to a torque to be generated by the motor or a response of the motor to the axis electric current value. | 04-28-2011 |
20110112724 | MOTOR CONTROL UNIT AND VEHICLE STEERING SYSTEM - A motor control unit includes a detected steering torque correction unit that corrects the detected steering torque that is detected by a torque sensor and then subjected to a limitation process by a steering torque limiter. When the absolute value of the detected steering torque is equal to or smaller than a predetermined value, the detected steering torque correction unit corrects the detected steering torque to 0. When the absolute value of the detected steering torque is larger than the predetermined value, the detected steering torque correction unit outputs the detected steering torque without correction. A PI control unit calculates the addition angle based on the deviation of the control torque obtained through correction by the detected steering torque correction unit from the command steering torque. | 05-12-2011 |
20110118937 | MOTOR CONTROL UNIT AND VEHICLE STEERING SYSTEM - When the estimated motor temperature becomes equal to or higher than the first predetermined temperature, an addition angle correction unit temporarily decreases the absolute value of the addition angle output from an addition angle limiter at time intervals. The addition angle correction unit makes the time interval shorter as the estimated motor temperature increases. When the time interval becomes equal to or shorter than the predetermined threshold, that is, when the estimated motor temperature becomes equal to or higher than the second predetermined temperature that is higher than the first predetermined temperature, the addition angle correction unit notifies a command current value changing unit of a current stop command. Thus, the γ-axis command current value is changed to 0, and therefore the steering mode is shifted to the manual steer mode. | 05-19-2011 |
20110118940 | MOTOR CONTROL UNIT AND VEHICLE STEERING SYSTEM - A motor is driven by the γ-axis current of a γδ coordinate system that is an imaginary rotating coordinate system. A command current value preparation unit sets the γ-axis command current value based on the command steering torque and the detected steering torque. The command current value preparation unit includes a command current increase/decrease amount calculation unit and an addition unit. The command current increase/decrease amount calculation unit calculates the current increase/decrease amount for the command current value based on the sign of the command steering torque and the deviation of the detected steering torque from the command steering torque. The current increase/decrease amount calculated by the command current increase/decrease amount calculation unit is added to the immediately preceding value of the command current value by the addition unit. Thus, the command current value in the present calculation cycle is calculated. | 05-19-2011 |
20120046832 | VEHICLE STEERING SYSTEM - A current increase-decrease amount (ΔI | 02-23-2012 |
20120055732 | ELECTRIC POWER STEERING SYSTEM - An electric power steering system includes a motor that applies assist force to a steering system, and updates a motor resistance (Rm) that is a value indicating a resistance of the motor. Specifically, the motor resistance (Rm) is updated on the basis of the fact that an induced voltage (EX) of the motor is smaller than a first determination value (GA). In addition, when the induced voltage (EX) is smaller than or equal to a second determination value (GB), a divided value that is obtained by dividing a motor voltage (Vm) by a motor current (Im) is set as a new motor resistance (Rm). | 03-08-2012 |
20120059550 | ELECTRIC POWER STEERING SYSTEM - An electric power steering system determines a steering state of a steering wheel on the basis of a current (Im) of a motor applying assist force to a steering system and a steering speed (ωs) of the steering wheel. A state where the steering wheel is retained at a position other than a neutral position is a retained state, and a state where the steering wheel is placed at the neutral position is a neutral state. When the steering speed (ωs) is lower than a determination value (ωa) and the motor current (Im) is larger than a reference value (Ix), it is determined whether the steering state is the neutral state. When the steering speed (ωs) is lower than the determination value (ωa), the motor current (Im) is larger than the reference value (Ix), and the steering state is determined to be the neutral state at immediately preceding determination, the steering state is determined to be the neutral state. | 03-08-2012 |
20120205186 | ELECTRIC POWER STEERING SYSTEM - An electric power steering system calculates a motor resistance Rm using a resistance map, and calculates an estimated inducted voltage based on a motor current and a motor voltage. If the estimated induced voltage is determined as being equal to or smaller than a determination value that is set in accordance with the current level, the electric power steering system calculates a motor resistance (estimated motor resistance Rma) and updates the resistance map based on the estimated motor resistance Rma. | 08-16-2012 |
20120299517 | ELECTRIC POWER STEERING SYSTEM - In an electric power steering system, a back electromotive force constant is calculated on the basis of a steering angular velocity and an estimated induced voltage. Then, a rotation angular velocity of a motor is calculated as an estimated rotation angular velocity on the basis of a motor current, a motor voltage, the back electromotive force constant and a motor resistance. | 11-29-2012 |
20130033216 | MOTOR CONTROL UNIT AND ELECTRIC POWER STEERING SYSTEM - An ECU that controls a motor includes: a target current value setting unit setting a target current; a voltage detecting unit detecting a detected voltage on the basis of a detection signal from a voltage sensor; a voltage calculation unit calculating an estimated voltage on the basis of a power supply voltage of a battery; and an induced voltage observer calculating an induced voltage generated at the motor using an inter-terminal voltage based on the estimated voltage when the target current is set to a value other than zero; whereas the induced voltage observer calculates the induced voltage using an inter-terminal voltage based on the detected voltage when the target current is set to zero. | 02-07-2013 |
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 |
20130074576 | ROAD FRICTION COEFFICIENT ESTIMATING UNIT AND ROAD FRICTION COEFFICIENT ESTIMATING METHOD - A road friction coefficient estimating unit calculates a tire sideslip angle and a cornering force, and estimates a road friction coefficient on the basis of the ratio of the calculated cornering force to the calculated tire sideslip angle. A vehicle travels on multiple road surfaces that differ in road friction coefficient, and tire sideslip angles and cornering forces on the road surfaces are detected in advance. The road friction coefficient estimating unit stores, in a memory, a correlation among the detected tire sideslip angles, the detected cornering forces, and the road friction coefficients in the form of numerical values or a mathematical expression, and estimates a road friction coefficient using the correlation stored in the memory. | 03-28-2013 |
20130076283 | MOTOR CONTROL UNIT AND MOTOR CONTROL UNIT FOR VEHICLE STEERING APPARATUS - A motor control unit controls a motor including a rotor and a stator facing the rotor. A current drive unit drives the motor at an axis current value of a rotating coordinate system that rotates in accordance with a control angle that is a rotational angle used in a control. An addition angle calculation unit calculates an addition angle to be added to the control angle. A control angle calculation unit obtains, at every predetermined calculation cycle, a present value of the control angle by adding the addition angle that is calculated by the addition angle calculation unit to an immediately preceding value of the control angle. A torque detection unit detects a torque that is other than a motor torque and that is applied to a drive target driven by the motor. A command torque setting unit sets a command torque to be applied to the drive target. An addition angle correction unit compares the command torque set by the command torque setting unit with the detected torque detected by the torque detection unit, and corrects the addition angle based on a comparison result. | 03-28-2013 |
20130304325 | MOTOR CONTROL DEVICE - A motor control device has characteristic information that indicates a correlation between a rotation speed and a current of a motor. The motor control device sets a rotation speed characteristic value that is a reference value of the rotation speed of the motor and a current characteristic value that is a reference value of the current of the motor on the basis of the characteristic information. The motor control device calculates an estimated rotation speed on the basis of a measured value of a voltage that is applied to the motor, a measured value of the current, the current characteristic value, a voltage characteristic value, the rotation speed characteristic value and a counter-electromotive force constant. | 11-14-2013 |