Abstract: An EGR valve control system includes a motor 5 exercising the opening and closing control of an EGR valve; a sensor 6 detecting the actual opening position of the EGR valve; and a motor control apparatus (control arithmetic section 1) computing a drive duty of the motor 5 based on a target opening position of the EGR valve and the actual opening position thereof detected by the sensor 6; and the control apparatus is arranged such that the control arithmetic section 1, when a target opening position of the EGR valve is set, computes an integral term based on the deviation between the target opening position and the actual opening position of the EGR valve, a proportional term and a differential term based on the change of the actual opening position of the EGR valve, and a feedforward term based on the change of the target opening position, respectively, and the control arithmetic section further exercises the opening and closing control of the EGR valve by computing the drive duty of the motor 5 by performing

Abstract: A brushless motor apparatus includes a fixedly arranged stator 14, a rotor 12 rotated in a manner sequentially excited by a plurality of excitation patterns, a magnetic-pole-position detecting magnet 16 fixed to the rotor and having twice the number of poles of the rotor, and a position detecting element 18 arranged opposite to the magnetic-pole-position detecting magnet and detecting the position of magnetic poles of the rotor, and further includes a motor drive circuit serving as a control such that when the stator is excited with a different excitation pattern between regular excitation patterns on normal operation at the time of phase matching carried out upon actuation of a power source, the rotation angle of the rotor is one-half the rotation angle corresponding to the regular excitation pattern.

Abstract: An EGR valve control system includes a motor 5 exercising the opening and closing control of an EGR valve; a sensor 6 detecting the actual opening position of the EGR valve; and a motor control apparatus (control arithmetic section 1) computing a drive duty of the motor 5 based on a target opening position of the EGR valve and the actual opening position thereof detected by the sensor 6; and the control apparatus is arranged such that the control arithmetic section 1, when a target opening position of the EGR valve is set, computes an integral term based on the deviation between the target opening position and the actual opening position of the EGR valve, a proportional term and a differential term based on the change of the actual opening position of the EGR valve, and a feedforward term based on the change of the target opening position, respectively, and the control arithmetic section further exercises the opening and closing control of the EGR valve by computing the drive duty of the motor 5 by performing

Abstract: A brushless motor apparatus includes a fixedly arranged stator 14, a rotor 12 rotated in a manner sequentially excited by a plurality of excitation patterns, a magnetic-pole-position detecting magnet 16 fixed to the rotor and having twice the number of poles of the rotor, and a position detecting element 18 arranged opposite to the magnetic-pole-position detecting magnet and detecting the position of magnetic poles of the rotor, and further includes a motor drive circuit serving as a control such that when the stator is excited with a different excitation pattern between regular excitation patterns on normal operation at the time of phase matching carried out upon actuation of a power source, the rotation angle of the rotor is one-half the rotation angle corresponding to the regular excitation pattern.