46results about How to "Good steering feel" patented technology

The invention provides a motor for a brushless DC motor, which has small torque ripple even if a trapezoidal wave current is supplied and has a small size and reduced motor noise. Respective phase current command values are calculated on the basis of vector control. Pseudo-vector control for controlling respective phases separately is used as current feedback control.

A motor (40) includes twelve stator teeth (52) arranged at equal intervals in the circumferential direction. A three phase first coil group (Sa) is formed by star-connecting of coils (S 1 , S 3 , S 5 , S 7 , S 9 and S 11 ) formed on the odd-numbered teeth (52), and a three phase second coil group (Sb) is formed by delta-connecting coils (S 2 , S 4 , S 6 , S 8 , S 10 and S 12 ) formed on the even-numbered teeth (52), the first coil group (Sa) and the second coil group (Sb) are connected in parallel.

A steer-by-wire steering system has a steering wheel actuator and a braking device that acts on the steering column. The braking device is activated when the vehicle steering wheel is to be blocked or at least sharply braked, such as when the steering stop is reached or a wheel goes over the edge of a curb. The braking device functions like a switchable freewheel.

A motor control signal output unit of an electric power steering system includes a feedback gain calculation unit (52), and a feedback control unit executes a feedback control with the use of a proportional gain (Kp) and an integral gain (Ki) that are calculated by the feedback gain calculation unit (52). The feedback gain calculation unit (52) sets the feedback gains to large values (Kp=P0, Ki=I0) when the absolute value of an assist gradient (α) is equal to or smaller than a predetermined value (α0) (|α|≦α0). On the other hand, when the absolute value of the assist gradient (α) exceeds the predetermined value (α0) (|α|>α0), the feedback gain calculation unit (52) sets the feedback gains to small values (Kp=p1, Ki=I1:P1<P0, I1<I0).

To reduce the cogging torque of servomotors, electric power steering motors, and others, there is provided a permanent magnet motor comprising: a rotor 10 comprising a rotor yoke 11 and a plurality of permanent magnets (M1-M10); and a stator 20 comprising a stator yoke 22, salient magnetic poles 21, and armature windings 23, wherein at least one of the permanent magnets is disposed in an adjustment position that is displaced from a corresponding reference position in at least one of the circumferential, radial, and axial directions of the rotor yoke, and the plurality of permanent magnets excluding the permanent magnet disposed in the adjustment position is disposed in the reference positions, and wherein the adjustment position is set so that the permanent magnet motor in which at least one of the plurality of permanent magnets is disposed in the adjustment position has a smaller cogging torque than a permanent magnet motor in which all of the plurality of permanent magnets are disposed in the reference positions; and a method for adjusting a cogging torque of a permanent magnet motor.

In a case where an engine ECU determines that the engine is started (restarted), the engine ECU notifies an EPSECU that cranking is to be performed to start the engine before performing the cranking. When such a notification is received, the EPSECU gradually reduces a current command limit value I*_lim and a boost voltage limit value Vbp_lim before the cranking is started.

The invention provides a safe electric power-steering device that produces a good steering feel, has the ability to disengage steering-wander suppression or steering-pull suppression, and produces an increased driver-burden reduction effect during steering wander or steering pull. [Solution] A motor-current correction-value computation unit that uses a motor-current correction value based on a motor correction signal to correct a current command value comprises the following: a straight-line-movement determination unit (110, 120) that determines whether a vehicle is moving in a straight line; an adaptive calculation unit that calculates the aforementioned motor correction signal (SG4) in accordance with the result of the straight-line-movement determination, a steering angle (theta), and an applied force (SAT estimate), at least, and outputs said motor correction signal (SG4); a vehicle-speed-sensitive gain unit (133) that outputs a vehicle-speed gain (Ga) that depends on the speed (V) of the vehicle; and an output calculation unit (105, 106) that multiples the motor correction signal (SG4) by the vehicle-speed gain (Ga) and outputs a motor-current correction value (Imc). The motor-current correction-value computation unit also has the ability to set thresholds for the motor correction signal and steering information and disengage steering-wander suppression or steering-pull suppression depending on the result of a condition determination performed on said motor correction signal and steering information and said thresholds.

In an electric power steering system, multiple cutouts (45) are formed in a flange portion (36) formed on an axial end portion (23a) of a ball screw nut (23) of a ball screw device that drives a rack shaft. In addition, a motor shaft (6) has a thin-plate portion (44) that extends on the radially outer side of the ball screw nut (23). When the thin-plate portion (44) that extends from the motor shaft (6) is swaged into the cutouts (45) that serve as engagement recesses that have side walls in the circumferential direction, the rotation of the ball screw nut (23) relative to the motor shaft (6) is restricted.

The invention discloses a differential torque power-assisted steering system used for a vehicle driving axle and a control method of the differential torque power-assisted steering system. A detection mechanism collects steering wheel rotating angle information, steering wheel rotating torque information, wheel speed information, battery voltage information and battery current information, and transmits the information to an electronic control unit; a working mode selection unit allows a driver to select different working modes of the differential torque power-assisted steering system, and transmits the working mode information to the electronic control unit; the electronic control unit controls switching of the working modes and controls an electromagnetic clutch, auxiliary motors and brakes of an execution mechanism to work according to the received information; and the auxiliary motors connected with left and right semi-shafts of the drive axle and the brakes arranged on driving wheels on the left and right sides are utilized, the driving wheels on the left and right sides have different driving torque or braking torque, and the vehicle produces an yaw moment to assist the driver to turn, so that force applied on a steering wheel by the driver is reduced, differential torque power-assisted steering is achieved, and the good steering handing feeling is provided for the driver.

A steering torque shift control amount calculation unit (31) calculates the steering torque shift control amount (εts) by multiplying the basic shift amount (εts_b) used as the basic compensation component by the transition coefficient (Kss). Then, the steering torque shift control amount (εts) is subjected to the low-pass filter process in an abrupt change prevention processing unit (32). An abrupt change prevention processing unit (40) is provided in the steering torque shift control amount calculation unit (31). The transition coefficient (Kss) is subjected to the low-pass filter process in the abrupt change prevention processing unit (40). The cutoff frequency of the low-pass filter that forms the abrupt change prevention processing unit (40) is set to a value lower than the cutoff frequency of the low-pass filter that forms the abrupt change prevention processing unit (32) that executes the low-pass filter process on the torque shift control amount (εts).