Abstract: An identification is made of an abnormal condition in a motor due to an influence of a disturbance voltage, without addition of hardware, by estimating the disturbance voltage based on a target voltage and actual current flowing in the motor.

Abstract: An electric power steering control device is provided, which comprises a vehicle speed detector, a steering torque detector, a steering shaft reaction torque meter, a motor speed detector, a motor acceleration detector, a steering torque detector for calculating a base target current, a damping compensator for finding a gain of a damping torque based on a steering shaft reaction torque to calculate a damping compensation amount based on the damping torque gain and motor speed, an inertia compensator for finding a gain of an inertia compensation torque based on the steering shaft reaction torque to calculate an inertia compensation amount based on the inertia compensation torque gain and motor acceleration, and an adder for compensating a base target current by a damping compensation amount and an inertia compensation amount to calculate a target current.

Abstract: An electric motor controller for a steering device that can apply an appropriate steering force to a steering wheel according to running conditions. An electric power steering controller of the present invention includes a steering shaft reaction force torque sensor for detecting a reaction force torque of a steering system, a superimposed reaction force torque calculating unit for multiplying a steering angle detected by the steering angle sensor by a gain to calculate a superimposed reaction force torque in the return direction of the steering wheel, and a control unit for controlling the gain so that the superimposed reaction force torque is reduced when a reaction force torque of the steering system is increased and the superimposed reaction force torque is increased when a reaction force torque of the steering system is decreased.

Abstract: There is provided an electric motor controller for a steering device that can give an appropriate steering force to a steering wheel according to running conditions. An electric power steering controller of the present invention is provided with a steering shaft reaction force torque sensor for detecting a reaction force torque of a steering system, a superimposed reaction force torque calculating unit for multiplying a steering angle detected by the steering angle sensor by a gain-to calculate a superimposed reaction force torque in the return direction of a steering wheel and a control unit for controlling the gain such that the superimposed reaction force torque is reduced when a reaction force torque of the steering system is large and the superimposed reaction force torque is increased when a reaction force torque of the steering system is small.

Abstract: An electric power steering apparatus having a steering system capable of flexibly setting a relationship between a steering angle of a steering wheel and a wheel angle of a tire. The first motor controls steering reaction force exerted on the steering wheel. The on-center region determination section determines whether the steering wheel is in a position of an on-center region. The tire reaction force torque detection section detects tire reaction force torque transferred from the tire. The control section calculates a steering torque based on the tire reaction force torque and a torque gain. This torque is detected by the tire reaction force torque detection section. And the control section controls the first motor to exert the steering reaction force corresponding to the above calculated steering torque on the steering wheel. This control section also sets the torque gain in case of determining of on-center region larger than that in case of determining of non-on-center region.

Abstract: System for detecting stability/instability of behavior of a motor vehicle upon occurrence of tire slip or lock. State of the motor vehicle is determined on the basis of an alignment torque (Ta) applied from a road and a side slip angle (&bgr;). By taking advantage of such torque/slip-angle characteristic that although the alignment torque is proportional to a side slip angle when the latter is small, the alignment torque becomes smaller as the side slip angle increases, a normal value is determined from a straight line slope and the side slip angle in a region where the latter is small. Unstable behavior of the motor vehicle is determined when deviation of actual measured value from the normal value increases. Further, unstable state is determined when the slope of the alignment torque for the slip angle departs significantly from that of approximate straight line slope.

Abstract: A judgment is made of an abnormal condition of a motor due to an influence of a disturbance voltage without addition of hardware by estimating the disturbance voltage on the basis of a target voltage and an actual current of the motor.

Abstract: An electric power steering control device is provided, which comprises a vehicle speed detector, a steering torque detector, a steering shaft reaction torque meter, a motor speed detector, a motor acceleration detector, a steering torque detector for calculating a base target current, a damping compensator for finding a gain of a damping torque based on a steering shaft reaction torque to calculate a damping compensation amount based on the damping torque gain and motor speed, an inertia compensator for finding a gain of an inertia compensation torque based on the steering shaft reaction torque to calculate an inertia compensation amount based on the inertia compensation torque gain and motor acceleration, and an adder for compensating a base target current by a damping compensation amount and an inertia compensation amount to calculate a target current.

Abstract: A method of controlling an automotive electric power steering system includes estimating a first road reaction torque from driver's steering torque detected by a steering torque detector. A second road reaction torque is estimated from the steering angle detected by a steering angle sensor. A returning torque compensator calculates a steering wheel-assisting torque from the second road reaction torque. An assisting torque is generated by an electric motor according to the result of the calculation, and is controlled in a direction to return the steering wheel to its center position. The returning torque compensator determines whether the steering angle sensor is faulty when the difference between the first and second road reaction torques is greater than a given value.

Abstract: A power steering control system is provided with a road surface reaction torque detector in which a motor inertia torque is subtracted from a value obtained by adding steering torque and motor torque, and the value is passed through two stages of primary filters to obtain a road surface reaction torque. In such a computation, the inertia term of the steering wheel manipulation force does not depend on frequency and high frequency components do not bring about any unusually large steering wheel return force. Therefore, a driver can drive without difficulty in adapting to the power steering.

Abstract: In an electric power steering control system, a road surface reaction torque estimator estimates a road surface reaction torque on the basis of steering wheel angle. A neutral point learning unit and a neutral point compensator learn a neutral point of the steering wheel on the basis of the road surface reaction torque with respect to the steering wheel angle. A return torque for returning the steering wheel to the neutral point is computed from a difference between a current angle of the motor and the learned neutral point. As a result, the steering wheel returns to the neutral point under the current driving condition without application of any force to the steering wheel by the driver.

Abstract: An electric power steering controller including a motor for generating torque for assisting the steering torque of a driver to assist the steering force of a steering system. The controller includes a road reaction torque detector for detecting road reaction torque received by tires from the surface of a road, and a road detection torque addition control for controlling the torque of the motor based on the road reaction torque. The electric power steering controller enables the steering wheel to be returned to its starting point without adding torque in a direction in which the driver returns the steering wheel when the driver contgrols the steering wheel with the small road reaction torque of the tires, for example, when turning at an intersection at a low speed or when turning at a gently curved portion of a road at a high speed.

Abstract: There is provided an electric motor controller for a steering device that can give an appropriate steering force to a steering wheel according to running conditions. An electric power steering controller of the present invention is provided with a steering shaft reaction force torque sensor for detecting a reaction force torque of a steering system, a superimposed reaction force torque calculating unit for multiplying a steering angle detected by the steering angle sensor by a gain to calculate a superimposed reaction force torque in the return direction of a steering wheel and a control unit for controlling the gain such that the superimposed reaction force torque is reduced when a reaction force torque of the steering system is large and the superimposed reaction force torque is increased when a reaction force torque of the steering system is small.

Abstract: An electric power steering controller and a control method for assisting a driver during handling a steering wheel in a condition of a small road surface reaction torque of a tire by generating an auxiliary return torque for letting the steering wheel return to its original position. A first road surface reaction torque is estimated from a steering torque of a driver detected by a steering torque detector, a motor acceleration detected by a motor acceleration detector, and a motor current detected by a motor current detector. A second road surface reaction torque is estimated from a steering angle detected by a steering angle sensor, and a vehicle speed detected by a vehicle speed detector. Then, first and second auxiliary return torque signals of the steering wheel are computed from a road surface reaction torque, and, based on the computed result, a torque of the motor is controlled in direction so the steering wheel is returned to its original position.

Abstract: In the conventional electric power steering control system, a steering force applied by a driver to a steering wheel is detected and a torque of a motor is determined on the basis of the detected steering force. In such a prior system, at the time of going round a gentle curve, going round an intersection at an extremely low speed or the like, any steering wheel return torque is not generated unless the driver returns the steering wheel, and drive feeling is not improved. First, a road surface reaction torque estimator 15 estimates a road surface reaction torque on the basis of a steering wheel angle. A neutral point learning unit 24 and a neutral point compensator 25 learn a neutral point of the steering wheel on the basis of the road surface reaction torque with respect to the steering wheel angle. A return torque for returning the steering wheel to the neutral point is computed from a difference between a current angle of the motor and the learned neutral point.

Abstract: The prior art electric power steering system in a vehicle has not be able to provide high steering-wheel returnability under every operating condition. A method of controlling an automotive electric power steering system in accordance with the present invention starts with estimating a first road reaction torque from driver's steering torque detected by a steering torque detector. A second road reaction torque is estimated from the steering angle detected by a steering angle sensor. A returning torque compensator calculates a steering wheel-assisting torque from the second road reaction torque. According to the result of the calculation, the assisting torque generated by an electric motor is controlled in the direction to return the steering wheel to its center position. The returning torque compensator judges that the steering angle sensor is at fault when the difference between the first and second road reaction torques is greater than a given value.

Abstract: In the conventional power steering control system, a road surface reaction torque is obtained by subtracting a motor inertia torque from a value obtained by adding a steering wheel steering torque and a motor torque and passing the value through a primary filter. In such computation, there is a disadvantage that high frequency components contained in steering wheel manipulation force brings about am unusually large steering wheel return force, and this gives a driver a feeling something like difficulty in adapting himself to the power steering. The system according to the invention is provided with a road surface reaction torque detector 115S in which a motor inertia torque is subtracted from a value obtained by adding a steering torque and a motor torque, and the value is passed through two stages of primary filters 100, 101 connected in two series thereby obtaining a road surface reaction torque.

Abstract: To estimate the rotation speed of the motor for assisting a steering torque regardless of the running state of a vehicle with accuracy, an application voltage estimation value obtained by subtracting a correction voltage obtained based on a detection current value detected by current detection means from the inter-terminal voltage measurement value of the motor is output and the rotation speed of the motor is estimated based on this application voltage estimation value and the detection current value.

Abstract: An electric power steering control system reducing steering torque without making a driver feel uncomfortable torque oscillation, including a rotation speed observer for estimating the rotation speed of a motor based on the output of a torque sensor high pass filter (HPF) and the output of a drive current HPF obtained by removing a steering frequency component from a drive current detection value.

Abstract: An automobile clutch control device comprises a target revolving speed generator 1 for generating a target revolving speed N.sub.r of an engine, a revolving speed detector 9 for detecting a revolving speed of the engine, a revolving speed error calculating unit 2 for calculating a target revolving speed error E.sub.r between the target revolving speed N.sub.r and the detected revolving speed N.sub.s, a first controller 11a for outputting a clutch drive signal U3 which corresponds to the calculated target revolving speed error E.sub.r, a revolving speed compensator 11b for outputting an engine revolving speed compensation signal U4, and an adder 11c for adding the clutch drive signal U3 and the revolving speed compensation signal U4 and outputting a target clutch drive signal U. The clutch 12 is controlled based on the output of the adder 11c.