Abstract: A motor controller capable of suppressing a large speed change generated at the time of changeover from a synchronous operation mode to a position feedback operation mode and implementing even acceleration characteristics regardless of the load torque by estimating a torque of a permanent magnet motor in the synchronous operation mode for driving the permanent magnet motor and setting an initial value of a current command value in a position sensor-less operation mode on the basis of information of the torque estimated value.

Abstract: In a steering-without-driving state, a larger current limit value, drive limit time and steering angle deviation threshold value are set than when a low-speed driving state occurs. An automatic parking mode is held until a time period over which a state where a motor current value of an electric motor which drives a steering mechanism is equal to the current limit value reaches the drive limit time. Even though the state where the motor current value is equal to the current limit value has continued over the drive limit time, the automatic parking mode is held during the steering angle deviation not exceeding the steering angle deviation threshold value. When the state where the motor current value is equal to the current limit value has continued over the drive limit time Ta and that the steering angle deviation exceeds the threshold value, the automatic parking control is cancelled.

Abstract: A brake application speed is compared with a speed threshold value so as to judge whether or not a braking operation being performed is an emergency braking operation. If not the emergency braking operation, an automatic parking mode is held. When the emergency braking operation is in effect, control information related to a state of an automatic parking control then is stored in a control information storage section, and the automatic parking control is cancelled. Thereafter, when a steering operation or a gearshift operation is performed before a cancellation of application of the brake is detected, the process is ended, and the control mode is held in an assist mode. When the application of the brake is cancelled with neither the steering operation nor the gearshift operation performed, the control information is read in so as to resume the automatic parking control.

Abstract: A synchronous motor including therein a three-phase inverter and position sensors, having a unit for calculating a digital input current value from the analog output of an input current detection circuit that detects the input current flowing into the DC input terminal of the three-phase inverter, and a digital feedback speed control unit for adjusting the amplitudes and frequency of the AC voltages outputted from the three-phase inverter in such a manner that the motor speed calculated by a motor speed calculation unit 41 on the basis of the outputs of the position sensors approaches a speed command value received by a communication reception unit from outside the synchronous motor. The synchronous motor further includes therein a communication transmission unit for transmitting the input current value and the motor speed to outside the synchronous motor.

Abstract: A rotation transmitting apparatus according to the present invention includes a first sun gear, a second sun gear, first planetary gears and second planetary gears. A carrier for supporting the respective planetary gears is integrally provided with a rotor of a speed change motor for changing a speed of rotation to be transmitted, so that the number of mesh portions in the gears is reduced. Further, the rotor is formed of a cylindrical shape and an input shaft for rotating the first sun gear is inserted into the rotor, so that a limited space is effectively used.

Abstract: A vehicle steering system includes: a steering actuator that imparts a steering force to a steering mechanism of a vehicle; an automatic steering controller that performs an automatic steering control by controlling the steering actuator; a driving state detector that detects a driving state of the vehicle during the automatic steering control; a threshold value setting unit that variably sets a threshold value for permitting an intervention in the automatic steering control; and an automatic steering intervention unit that intervenes in the automatic steering control based on a threshold value set by the threshold value setting unit.

Abstract: A differential gear apparatus according to the present invention comprises a first sun gear coupled to a first shaft to be rotated in conjunction with the first shaft, a second sun gear coupled to a second shaft to be rotated in conjunction with the second shaft, a first planetary gear meshed with the first sun gear, a second planetary gear rotated with the first planetary gear and meshed with the second sun gear, a carrier supporting the first and second planetary gears, and a housing supporting the second shaft upon rotation, wherein the sun gears and the planetary gears have profile shifted teeth of which addendum modifications are different at the positions in a flank width direction and a nut screwed on the mid way of the second shaft, and a through hole disposed at a position facing the nut are provided.

Abstract: A field weakening vector controller is disclosed which calculates a d-axis current command value for a power converter to drive a permanent magnet synchronous motor. The field weakening vector controller includes a stabilization calculator, a d-axis current command calculator, a q-axis current command calculator, and a phase calculator. The d-axis current command calculator corrects the d-axis current command value, while the stabilization calculator calculates a product of the phase error and the d-axis command value. The q-axis current command calculator corrects the q-axis current command value using this product.

Abstract: In order to prevent a short circuit of top and bottom arms of a motor driving IC when noise is added to six control signals for controlling six switching elements, there is provided a semiconductor device for driving a motor, being sealed with resin as one package and comprising: six switching elements for driving a three-phase motor; three output terminals for outputting voltages to the three-phase motor; at least one driving circuit for driving the six switching elements; three control signal input terminals; and a function) of generating six control signals for control of the six switching elements based on three control signals inputted through the three control signal input terminals.

Abstract: The synchronous motor driving apparatus including position sensors provided in the synchronous motor, a current polarity detection circuit for detecting the polarities of the currents in the respective phase windings of the synchronous motor, an inverter driving the synchronous motor, a motor speed calculation unit calculating the rotational speed of the synchronous motor depending on the output signals from the position sensors, a speed control unit outputting a first voltage adjusting component (q-axis current command value Iq*) to cause the rotational speed of the synchronous motor to approach a speed command value and a phase control unit outputting a second voltage adjusting component (d-axis current command value Id*) to cause the phase differences between the phases of the position sensor signals and of the currents in the respective phase windings of the synchronous motor to become a predetermined value.

Abstract: An automatic parking control is cancelled when a motor current has not yet reached a maximum current value Imax with a steering angle deviation exceeding a deviation threshold value. In addition, the automatic parking control is cancelled when a steering speed has not yet reached a maximum steering speed with a state where the motor current has reached and remains at the maximum steering speed continuing over a first time period. On the other hand, when a state where the steering speed has reached and remains at the maximum steering speed continues over a second time period, it is determined that there occurs an output shortage of a steering actuator, an automatic parking condition is recalculated, so as to allow the automatic parking continue to continue.

Abstract: There is provided a vehicle steering system which includes an electric motor for imparting a steering force to a steering mechanism of a vehicle and an automatic parking controller for executing an automatic parking control by controlling the electric motor, wherein the automatic parking controller controls an energizing voltage of the electric motor by imparting a square wave to the electric motor and increasing/decreasing a neutral point voltage of a winding of the electric motor.

Abstract: In a system in which current is detected in an inexpensive manner or in a system in which a position detector is omitted, the present invention provides a high-efficiency vector controller for a permanent magnet motor that can minimize current at the same torque even when there is setting error (R?R*) in resistance. Even when a current value commanded for the d-axis is set to zero, a virtual inductance value calculated from a detected q-axis current value is used for output voltage value calculation and phase error estimation calculation; so even if there is setting error (R?R*) in resistance, current can be minimized at the same torque and thereby the present invention can provide a high-efficiency vector controller for a permanent magnet motor.

Abstract: A vehicle steering system is provided which includes a variable angle ratio mechanism for changing an angle ratio of a steering angle of a steering member to a turning angle of a steering mechanism, the variable angle ratio mechanism including a first sun gear connected to a steering column, a second sun gear connected to the steering mechanism, and planetary gears each having a first toothed portion and a second toothed portion which are adapted to mesh with the first and second sun gears respectively, and are arranged to be spaced apart from each other in a tooth face width direction, the first toothed portion and the second toothed portion being formed integrally through forging.

Abstract: A brake application speed is compared with a speed threshold value so as to judge whether or not a braking operation being performed is an emergency braking operation. If not the emergency braking operation, an automatic parking mode is held. When the emergency braking operation is in effect, control information related to a state of an automatic parking control then is stored in a control information storage section, and the automatic parking control is cancelled. Thereafter, when a steering operation or a gearshift operation is performed before a cancellation of application of the brake is detected, the process is ended, and the control mode is held in an assist mode. When the application of the brake is cancelled with neither the steering operation nor the gearshift operation performed, the control information is read in so as to resume the automatic parking control.

Abstract: A vehicle steering system includes: a steering actuator that imparts a steering force to a steering mechanism of a vehicle; an automatic steering controller that performs an automatic steering control by controlling the steering actuator; a driving state detector that detects a driving state of the vehicle during the automatic steering control; a threshold value setting unit that variably sets a threshold value for permitting an intervention in the automatic steering control; and an automatic steering intervention unit that intervenes in the automatic steering control based on a threshold value set by the threshold value setting unit.

Abstract: An automatic parking control is cancelled when a motor current has not yet reached a maximum current value Imax with a steering angle deviation exceeding a deviation threshold value. In addition, the automatic parking control is cancelled when a steering speed has not yet reached a maximum steering speed with a state where the motor current has reached and remains at the maximum steering speed continuing over a first time period. On the other hand, when a state where the steering speed has reached and remains at the maximum steering speed continues over a second time period, it is determined that there occurs an output shortage of a steering actuator, an automatic parking condition is recalculated, so as to allow the automatic parking continue to continue.

Abstract: In a steering-without-driving state, a larger current limit value, drive limit time and steering angle deviation threshold value are set than when a low-speed driving state occurs. An automatic parking mode is held until a time period over which a state where a motor current value of an electric motor which drives a steering mechanism is equal to the current limit value reaches the drive limit time. Even though the state where the motor current value is equal to the current limit value has continued over the drive limit time, the automatic parking mode is held during the steering angle deviation not exceeding the steering angle deviation threshold value. When the state where the motor current value is equal to the current limit value has continued over the drive limit time Ta and that the steering angle deviation exceeds the threshold value, the automatic parking control is cancelled.

Abstract: A vehicle steering system includes: a control member that is manipulated by a driver for controlling a direction of a vehicle; a steering mechanism that turns steered road wheels in response to manipulation of the control member; an automatic driving mode setting unit that enables an automatic driving control for an automatic driving mode; a plurality of vehicle sensors for detecting various kinds of information which represent behaviors of the vehicle; an output gain switch that switches an output gain for a predetermined vehicle sensor of the plurality of vehicle sensors so as to output an appropriate output for the automatic driving mode in response to setting of the automatic driving mode by the automatic driving mode setting unit; and an automatic steering controller that automatically controls the steering mechanism while referring to outputs of the plurality of vehicle sensors in the automatic driving mode.

Abstract: In an automatic parking mode, a target path is obtained, and a vehicle is automatically controlled to follow the target path. When a driver intervenes steering of the vehicle, an anticipated course to be taken by the vehicle to follow after the intervention to the steering is calculated as a revised path. When the vehicle follows the revised path, if the vehicle is expected to be brought into contact with an obstacle, firstly, an alarm is raised. When an avoidance operation is performed after the alarm, an anticipated course to be taken by the vehicle to follow after the avoidance operation is re-calculated as a revised path. If no avoidance operation is performed or if the vehicle is expected to be brought into contact with the obstacle even when the vehicle follows the revised path, forced brakes are applied to the vehicle, and the automatic parking control is halted.