Abstract: While a production apparatus is operating, a computation unit of an analysis device performs main predictive computation on an acceptability in real time by using one or more operating predictors selected from among a plurality of predictors. When the main predictive computation is not performed, the computation unit performs subsidiary predictive computation on the acceptability by using one or more subsidiary predictors that are not selected from among the plurality of predictors. The computation unit performs processing of interchanging the operating predictors and the subsidiary predictors based on prediction accuracies of the operating predictors and prediction accuracies of the subsidiary predictors.

Abstract: While a production apparatus is operating, a computation unit of an analysis device performs main predictive computation on an acceptability in real time by using one or more operating predictors selected from among a plurality of predictors. When the main predictive computation is not performed, the computation unit performs subsidiary predictive computation on the acceptability by using one or more subsidiary predictors that are not selected from among the plurality of predictors. The computation unit performs processing of interchanging the operating predictors and the subsidiary predictors based on prediction accuracies of the operating predictors and prediction accuracies of the subsidiary predictors.

Abstract: To provide an analysis apparatus capable of improving the accuracy of analysis results. An analysis apparatus makes predictions about the quality of conditions of a production facility or the quality of conditions of a production object in a process of producing a crankshaft as the production object by a grinder as the production facility. The analysis apparatus includes the plurality of predictors making predictions about the quality by using different analysis methods based on data concerning the production facility, a selection unit selecting the plurality of predictors in use from the plurality of predictors, and an overall predictor calculating a comprehensive prediction result about the quality based on the plurality of prediction results obtained by the plurality of predictors in use selected by the selection unit.

Abstract: 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.

Abstract: 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).

Abstract: A motor is driven by the ?-axis current of a ?? coordinate system that is an imaginary rotating coordinate system. A command current value preparation unit sets the ?-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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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).

Abstract: An angular velocity estimate (?e) 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 (?e) 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.

Abstract: 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.

Abstract: A steering assist operation is performed, which includes a motor control unit that controls a motor, and the steering assist operation does not require a rotational angle sensor. 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, which is calculated by a control angle calculation unit. The 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. 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 from a command torque set by a command torque setting unit.

Abstract: 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.

Abstract: 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).

Abstract: 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.

Abstract: A rotation angle calculation unit calculates a zero-crossing time point when a zero-crossing is detected for an output signal V1 or an output signal V2. The rotation angle calculation unit calculates a time interval (zero-crossing interval) between the zero-crossing time point calculated this time for the output signal V1 or V2 for which the zero-crossing is detected and the zero-crossing time point calculated the last time for this output signal. The rotation angle calculation unit identifies the magnetic pole presently sensed by a magnetic sensor corresponding to the output signal for which the zero-crossing is detected, based on the calculated zero-crossing interval, the sum of zero-crossing intervals that is calculated last based on the output signals of the magnetic sensor over one turn of a rotor, the rotation direction of the rotor, and the content of an amplitude correction table (a first or second table) for the magnetic sensor.

Abstract: 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 ?^L. A high speed region position estimating portion is designed to be suitable for when the motor is operating in a high speed region, and estimates a high speed estimated rotational position ?^H. A dividing portion obtains a divided estimated rotational position ?^M by internally dividing the low speed estimated rotational position ?^L and the high speed estimated rotational position ?^H. A rotation speed calculating portion obtains a rotation speed ? of a rotor based on an output signal from a steering sensor. The rotational position of the rotor is then obtained by selecting one of i) the low speed estimated rotational position ?^L, the high speed estimated rotational position ?^H, or the divided estimated rotational position ?^M, based on that rotation speed ?.

Abstract: An angular velocity estimate (?e) 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 (?e) 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.

Abstract: 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).