Abstract: A motor driving control method in which when the steering angular velocity is lower than a predetermined reference angular velocity, an actual motor drive current is inferred from a back electromotive voltage and an applying voltage in a three-phase brushless motor, and a limitation on the peak level of each of three-phase alternating current command waves is mitigated by permitting the interval between a pair of intersection points of a peak area of each of the three-phase alternating current command waves with a peak point neighborhood of a triangle wave to become approximately the same length as a dead time.

Abstract: A method for easily applying a coating agent to an electronic circuit board accommodated in a housing without leaving uncoated portions. The method includes mounting the electronic circuit board to the housing, performing an electrical connection process in the electronic circuit board, and filling the housing with the coating agent (anti-moisture agent) to immerse the electronic circuit board in the coating agent.

Abstract: A motor driving control method in which when the steering angular velocity is lower than a predetermined reference angular velocity, an actual motor drive current is inferred from a back electromotive voltage and an applying voltage in a three-phase brushless motor, and a limitation on the peak level of each of three-phase alternating current command waves is mitigated by permitting the interval between a pair of intersection points of a peak area of each of the three-phase alternating current command waves with a peak point neighborhood of a triangle wave to become approximately the same length as a dead time.

Abstract: An electronic control unit includes an electronic circuit substrate and a casing that accommodates the electronic circuit substrate. A plurality of electronic components are mounted on the electronic circuit substrate. A plurality of connector terminals extend through a side wall of the casing for electrically connecting the electronic circuit substrate to external wires. A retainer portion capable of retaining liquid seal agent is arranged at an inner side of the wall through which the connector terminals extend.

Abstract: A method for easily applying a coating agent to an electronic circuit board accommodated in a housing without leaving uncoated portions. The method includes mounting the electronic circuit board to the housing, performing an electrical connection process in the electronic circuit board, and filling the housing with the coating agent (anti-moisture agent) to immerse the electronic circuit board in the coating agent.

Abstract: An electronic control unit includes an electronic circuit substrate and a casing that accommodates the electronic circuit substrate. A plurality of electronic components are mounted on the electronic circuit substrate. A plurality of connector terminals extend through a side wall of the casing for electrically connecting the electronic circuit substrate to external wires. A retainer portion capable of retaining liquid seal agent is arranged at an inner side of the wall through which the connector terminals extend.

Abstract: The invention provides an electric power steering apparatus which can detect a ground fault of an angular resolver without fault. Values of a first resistance (R1), a second resistance (R2), a third resistance (R3) and a fourth resistance (R4) are set such that a difference between a minimum output potential (Vout Min) of a first differential amplifier (OP1) at a time when an angular resolver is not in a ground fault which may be generated on the basis of a dispersion of the first resistance (R1), the second resistance (R2), the third resistance (R3) and the fourth resistance (R4), and a direct-current resistance component (Rdc) of the angular resolver, and a maximum potential (Vout Max) at a time when the angular resolver is in the ground fault becomes equal to or more than a predetermined margin for preventing an erroneous ground fault detection in a CPU (62) side.

Abstract: An electric power steering apparatus includes a first resolver whose pole pair number is ‘m’ and a second resolver whose pole pair ‘n’. The electric power steering apparatus further includes a torsion calculating means which calculates the a torsion angle of the torsion bar from a difference between the rotating angle detected by the first resolver and the rotating angle detected by the second resolver. The torsion calculating means compensates the angle difference by a compensation value obtained by a table on the basis of the value obtained by multiplying an electrical angle of the first resolver by ‘n’ and the value obtained by multiplying an electrical angle of the second resolver by ‘m’.

Abstract: The invention provides an electric power steering apparatus which can detect a ground fault of an angular resolver without fault. Values of a first resistance (R1), a second resistance (R2), a third resistance (R3) and a fourth resistance (R4) are set such that a difference between a minimum output potential (Vout Min) of a first differential amplifier (OP1) at a time when an angular resolver is not in a ground fault which may be generated on the basis of a dispersion of the first resistance (R1), the second resistance (R2), the third resistance (R3) and the fourth resistance (R4), and a direct-current resistance component (Rdc) of the angular resolver, and a maximum potential (Vout Max) at a time when the angular resolver is in the ground fault becomes equal to or more than a predetermined margin for preventing an erroneous ground fault detection in a CPU (62) side.

Abstract: An electric power steering apparatus includes a first resolver whose pole pair number is ‘m’ and a second resolver whose pole pair ‘n’. The electric power steering apparatus further includes a torsion calculating means which calculates the a torsion angle of the torsion bar from a difference between the rotating angle detected by the first resolver and the rotating angle detected by the second resolver. The torsion calculating means compensates the angle difference by a compensation value obtained by a table on the basis of the value obtained by multiplying an electrical angel of the first resolver by ‘n’ and the value obtained by multiplying an electrical angle of the second resolver by ‘m’.

Abstract: The vehicle operation control apparatus multiplies the variable gain G controlled based on the vehicle velocity V, the steering angle &thgr;h, the steering angle velocity &ohgr;h and the actual steering angle &thgr;T with the steering angle &thgr;h, and controls the actual steering angle &thgr;T of the driven wheels on a result of this multiplication. Consequently, the additional turning time gear ratio Ga1 or the turning-back gear ratio Ga2, set up individually, can be selected depending on the turning direction of the steering wheel. Therefore, the steering feeling both at the time of additional turning and turning-back can be improved.

Abstract: The vehicle operation control apparatus multiplies the variable gain G controlled based on the vehicle velocity V, the steering angle &thgr;h, the steering angle velocity &ohgr;h and the actual steering angle &thgr;T with the steering angle &thgr;h, and controls the actual steering angle &thgr;T of the driven wheels on a result of this multiplication. Consequently, the additional turning time gear ratio Ga1 or the turning-back gear ratio Ga2, set up individually, can be selected depending on the turning direction of the steering wheel. Therefore, the steering feeling both at the time of additional turning and turning-back can be improved.

Abstract: An apparatus for preventing torque variation in a digitally controlled servomotor. Electrical angles .theta..sub.1 and .theta..sub.2 of the exciting magnetic field or the armature coil at respective timings of detecting and controlling a load current are obtained. The current is dq-transformed with .theta..sub.1 and inverse-dq-transformed with .theta..sub.2. As a result, even if there is a displacement of the actual electrical angle owing to the rotation of the armature during computing, it is possible to execute accurate current control. Further, at the time of calibration of the control system, the load currents are detected to be dq-transformed. From the d-axis components and q-axis components, values related to the offset and the amplification factor of the current detection systems are calculated. During the actual operation of the servomotor, the detected current value is corrected using the values. Further, the detection of the load current is performed plural times in one control cycle.