Abstract: A first-stage phase compensation means, a second-stage phase compensation means, and a third-stage phase compensation means are configured in such a way that a frequency at which a phase calculated through the transfer function of the first-stage phase compensation means becomes maximal and a frequency at which a phase calculated through a transfer function of the first-stage phase compensation means and the third-stage phase compensation means becomes maximal coincide with each other; a motor for generating assist torque is controlled, based on a torque signal to which the first-stage phase compensation means, the second-stage phase compensation means, and the third-stage phase compensation means have applied phase compensation.

Abstract: A motor-driven power steering control apparatus for determining pertinent timings for starting/stopping application of steering assist torque includes a motor for applying an assist torque, a sensor for detecting a steering torque, a driving unit for operating the motor in dependence on a detected steering torque, a command unit for commanding starting and stopping of operation of the motor, and a motor operation decision unit. When stopping of operation of the motor is commanded by the command unit, the motor operation decision unit stops driving operation of the motor while commanding the driving unit to stop application of the steering assist torque when a state in which a steering torque is not greater than a predetermined value for stoppage has continued for a predetermined time period.

Abstract: A motor-driven power steering control apparatus for determining pertinent timings for starting/stopping application of steering assist torque includes a motor (7) for applying an assist torque, a sensor (2) for detecting a steering torque, a driving unit (13,14,121,124) for operating the motor (7) in dependence on a detected steering torque, a command unit (12;122,123) for commanding starting and stopping of operation of the motor (7), and a motor operation decision unit (12;122,123). When stopping of operation of the motor (7) is commanded by the command unit (122,123), the motor operation decision unit (122,123) stops driving operation of the motor (7) while commanding the driving unit (13,14,121,124) to stop application of the steering assist torque when a state in which a steering torque is not greater than a predetermined value for stoppage has continued for a predetermined time period.

Abstract: A steering control device is provided, which comprises a motor driving circuit for driving a motor and a microprocessor for supplying an applied voltage signal, which is found based on a motor current detection value detected by a motor current detecting unit, a motor voltage detection value detected by a motor voltage detecting unit, a steering torque detected by a torque sensor and a vehicle speed detected by a vehicle speed sensor, to the motor driving circuit such that the motor driving circuit increases or decreases the motor current according to an average value of motor current detection values over a time period and increases or decreases the motor current by detecting that a steering is in the vicinity of a maximum steering angle based on the detected steering torque.

Abstract: A steering control device is provided, which comprises a motor driving circuit for driving a motor and a microprocessor for supplying an applied voltage signal, which is found based on a motor current detection value detected by a motor current detecting unit, a motor voltage detection value detected by a motor voltage detecting unit, a steering torque detected by a torque sensor and a vehicle speed detected by a vehicle speed sensor, to the motor driving circuit such that the motor driving circuit increases or decreases the motor current according to an average value of motor current detection values over a time period and increases or decreases the motor current by detecting that a steering is in the vicinity of a maximum steering angle based on the detected steering torque.

Abstract: An electric power steering device constructed to detect a steering force by a driver and a vehicle speed respectively by a torque sensor and a vehicle speed sensor, set a steering force assisting current for a motor by a steering force assisting current setter using the detected steering force and the detected vehicle speed, set an upper limit value of a motor current by a motor current upper limit value setter based on a power function of a deviation between the set steering force assisting current and a predetermined motor current reference value, and perform overheat protection by setting an upper limit of a motor current applied by a motor driving circuit based on an integrated value of the motor current squared, whereby a problem of an insufficient steering assisting force when stationary steering is repeated many times while parking in a garage in a narrow parking area is solved.

Abstract: To estimate the rotation speed of the motor for assisting a steering torque regardless of the running state of a vehicle with accuracy, an application voltage estimation value obtained by subtracting a correction voltage obtained based on a detection current value detected by current detection means from the inter-terminal voltage measurement value of the motor is output and the rotation speed of the motor is estimated based on this application voltage estimation value and the detection current value.

Abstract: A motor controller is provided which improves response to control inversion of a motor, and which also improves controllability and driving comfort when applied to electric power steering. In the motor controller a bridge circuit 5 is formed which includes switching elements 3a to 3d which are driven to control the motor 2 in a direction of conduction, a drive system is switched between a single-phase one-sided chopper system and either a single-phase double-sided chopper system or a double-phase double-sided chopper system based on detected states of an apparatus or the amount of control, so as to control the motor 2 with a drive system suitable for each state of the apparatus.