41results about How to "Steering feeling can be improved" patented technology

A first compensation torque T1, a second compensation torque T2 and a third compensation torque T3 are added to a basic assist torque Tas. In this case, the second compensation torque T2 and the third compensation torque T3 are corrected by multiplying them by a common control gain G that is determined by the steering torque Th and the vehicle speed v. Therefore, since the two compensation control amounts are corrected through multiplication by the common control gain G, no interference occurs between the compensation controls. Besides, when the direction in which the total (T2+T3) of the pre-correction second compensation torque T2 and the pre-correction third compensation torque T3 acts is the same direction as the steering torque Th, the multiplication by the control gain G is avoided.

A system and an operating method are provided for supporting lane keeping of a vehicle equipped with a steering device. The system and operating method include providing vehicle related information; providing environment related information; combining vehicle and environment related information; predicting a future trajectory of the vehicle based on vehicle and environment related information; estimating a desired lateral lane position of the vehicle and / or a guiding force; comparing the future trajectory and the desired lateral lane position; deciding if a guiding force is to be provided to the steering device; and, if guiding force is to be provided, defining an amount of said guiding force depending on a hierarchically ordered set describing a predetermined driving behavior of the vehicle, adapting the amount of guiding force depending on the direction in which the vehicle is intended to move and activating one or more actuators for supplying the adapted amount of guiding force to the steering device.

A method for controlling an electric assist motor for providing steering assist in response to a steering sensed torque signal includes filtering the sensed steering torque signal to provide a low frequency torque signal and a high frequency torque signal. A low frequency assist torque signal is determined as a function of the low frequency torque signal. A high frequency assist gain signal is determined as a function of the sensed torque signal and a sensed vehicle speed. The high frequency assist gain signal is applied to the high frequency torque signal to determine a high frequency assist torque signal. A torque command signal is determined as a function of the low frequency assist torque signal and the high frequency assist torque signal. The electric assist motor is commanded to provide steering assist in accordance with the torque command signal.

Apparatus and method is presented for enabling a power steering system comprising an accumulator, a reservoir, and an electronically controlled closed-center control valve assembly for selectively fluidly coupling the accumulator and reservoir to a double-acting power cylinder of a power steering system to function in the manner of a force-based power steering system.

Brushless motor is provided which includes an outer stator and an inner rotor having a plurality of permanent magnets. One or inner surface of the outer stator, opposed to the inner rotor, is covered with a cover formed of a magnetic material and in the shape of a cylinder of a small wall thickness. The magnetic cover has a plurality of slits inclined with respect to the rotational axis of the inner rotor. Magnetic portions formed or left between the slits of the cover are also inclined with respect to the rotational axis of the inner rotor. With such magnetic portions, boundaries between magnetic poles are virtually inclined with respect to the rotational axis of the inner rotor, so that undesired cogging torque of the motor can be minimized.

A control device in an electric power steering device calculates a first assist component based on steering torque and a vehicle speed. The control device also calculates a compensation component associated with an reverse input and calculates a steered angle command value based on an addition value of the compensation component and basic drive torque that is an addition value of the steering torque and the first assist component, produces a second assist component by performing steered angle feedback control that causes the steered angle of a vehicle to follow the steered angle command value. The control device controls drive of a motor based on an assist command value that is an addition value of the first assist component and the second assist component.

The rotational angle correction controller includes a second correction amount-computing part that computes a second correction amount ε2 for correcting the rotational angle θ such that the phase is shifted in the steering operation direction, and the rotational angle correction controller performs the rotational angle correction by adding the computed second correction amount ε2 to the rotational angle θ. Further, the rotational angle correction controller includes a stuck steering wheel determining part that detects the significant reduction in the follow-up performance of the motor with respect to the steering operation that occurs due to the existence of the deceleration section caused by execution of the above-described electric current restriction, that is, the occurrence of the stuck steering wheel. When the occurrence of the stuck steering wheel is detected, the second correction amount-computing part changes the second correction amount ε2 to a value (ε2′) larger than the normal value.

It is one object of the present invention to provide a steering device for a vehicle improving a resolution of detecting a steering reaction force thereby to control precisely a reaction actuator and to improve a steering feeling.The steering device for the vehicle is equipped with a reaction actuator 19 acting a steering reaction force on a steering wheel 1. This device further includes a steering angle sensor 11 detecting a steering angle δh of the steering wheel 1, a controller 20 controlling the reaction actuator 19 according to the steering angle δh, a torque sensor 12 detecting a steering torque Th acted on the steering wheel 1. The controller 20 controls in a feedback way the reaction actuator 11 based on the steering torque Th in a predetermined range including a middle point of the steering angle. The controller 20 drives, in a open-loop way without feed-backing the steering torque Th, the reaction actuator 19 out of the predetermined range of the steering angle δh.

A method is provided for assisting a driver of a vehicle during operation by providing the driver with a desired steering feel, wherein the vehicle includes a steering arrangement including a manually operated steering device, at least one pair of ground engaging members and a mechanical interconnection between the steering device and the ground engaging members. The method includes detecting a steering angle and determining a desired steering device guiding force based on the detected steering angle, providing the driver with the desired steering feel based on the desired steering device guiding force, and detecting the steering angle in a position at a ground engaging member side of an elastic steering force transmitting element in the steering arrangement.

A control device 50 that drives and controls a brushless motor 3 of a four-pole 24-slot configuration includes: a base current calculation section 52 that calculates fundamental-wave current indicating a winding current value associated with maximum torque control; a correction component calculation section 59 that calculates 12th-order first higher harmonic wave component B sin 12(θ+β) to cancel a torque ripple of magnet torque, and 12th-order second higher harmonic wave component A sin 12(θ+α) to cancel a torque ripple of reluctance torque, based on a phase current value detected by a current sensor 64; a correction map 58 in which relation between phase current and parameters A, B, α, and β of the both higher harmonic wave components is stored; and a current correction section 60 that corrects supply current by superimposing each 12th-order higher harmonic wave component on the fundamental-wave current in order to create current command values Id′ and Iq′.

A method and system for inhibiting torque steer in a vehicle equipped with steerable wheels that are power driven. The method determines a maximum engine torque limit, determines an estimated driver-desired torque, and controls the actual torque, by adjustment of the throttle angle, to be the smaller of the maximum engine torque limit and the estimated driver-desired torque. Sensors measure steering angle and transmission gear position and a calculator determines the maximum engine torque limit based upon the steering angle and transmission gear position. Further sensors measure engine speed, throttle angle, and atmospheric pressure, and a calculator estimates driver-desired torque based upon the measured engine speed, throttle angle, and atmospheric pressure. A comparator selects the lower of the maximum engine torque limit and the driver-desired engine torque and uses the selected torque to control throttle angle to inhibit torque steer.

An electric power steering device includes a power transmission joint (21) which coaxially couples an output shaft of a steering assist electric motor to an input shaft of a speed reduction mechanism for power transmission. The power transmission joint (21) includes first and second engagement members (41, 42) and an elastic member (43) disposed between the first and second engagement members (41, 42). The elastic member (43) includes an annular main body (44) and a plurality of engagement arms (45) provided at a predetermined interval circumferentially of the main body (44). The engagement arms (45) are engaged with engagement projections (55, 56) of the first and second engagement members (41, 42) circumferentially (X1) of the main body (44). Power transmission faces (46, 460) of the engagement arms (45) include power transmission faces (460) each having a relatively great interference (d1) and power transmission faces (46) each having a relatively small interference (d2).

An electric power steering apparatus includes a driving target value setting unit for setting a driving target value of an electric motor; a steering acceleration detecting unit for detecting or estimating a steering acceleration; a correction amount computing unit for computing a control correction amount in accordance with the steering acceleration; a vehicle acceleration detecting unit for detecting an acceleration of a motor vehicle; an acceleration adaptive gain setting unit for setting a gain in accordance with an acceleration of a motor vehicle; a multiplication unit for determining a gain adjusted control correction amount by multiplying the control correction amount with the acceleration adaptive gain; a correcting unit for correcting the driving target value on the basis of the gain adjusted control correction amount; and motor driving units for driving the electric motor on the basis of the corrected driving target value.

A first compensation torque T1, a second compensation torque T2 and a third compensation torque T3 are added to a basic assist torque Tas. In this case, the second compensation torque T2 and the third compensation torque T3 are corrected by multiplying them by a common control gain G that is determined by the steering torque Th and the vehicle speed v. Therefore, since the two compensation control amounts are corrected through multiplication by the common control gain G, no interference occurs between the compensation controls. Besides, when the direction in which the total (T2+T3) of the pre-correction second compensation torque T2 and the pre-correction third compensation torque T3 acts is the same direction as the steering torque Th, the multiplication by the control gain G is avoided.

An electric power steering system which assists in steering by driving an electric motor in accordance with an operation of a steering member, comprising a drive gear connected to a rotation shaft of the electric motor and a driven gear securely fitted on a steering shaft so as to mesh with the drive gear, wherein the driven gear includes a gear body and a ring element that is mounted on the gear body in such a manner as to slide relative to the gear body.

An electric power steering apparatus includes a driving target value setting unit for setting a driving target value of an electric motor; a steering acceleration detecting unit for detecting or estimating a steering acceleration; a correction amount computing unit for computing a control correction amount in accordance with the steering acceleration; a vehicle acceleration detecting unit for detecting an acceleration of a motor vehicle; an acceleration adaptive gain setting unit for setting a gain in accordance with an acceleration of a motor vehicle; a multiplication unit for determining a gain adjusted control correction amount by multiplying the control correction amount with the acceleration adaptive gain; a correcting unit for correcting the driving target value on the basis of the gain adjusted control correction amount; and motor driving units for driving the electric motor on the basis of the corrected driving target value.

A power steering system includes a hydraulic power cylinder having a first and a second hydraulic chambers, for assisting a steering force of a steering mechanism, a first and a second oil passages respectively connected to the first and second hydraulic chambers, a reversible pump discharging operating oil and providing oil pressure to the hydraulic power cylinder through the first and second oil passages, and a motor connected to the reversible pump and rotating the reversible pump in normal and reverse directions. A steering load detection unit detects a steering load of a steering wheel for steering of the steered road wheels, and a motor control unit outputs a control signal to the motor to bring an actual oil pressure generated by the reversible pump closer to a desired oil pressure determined based on the detected steering load. A discharge amount per rotation of the reversible pump is smaller than or equal to 5 cc.

A rack bar supporting device for a vehicle steering apparatus, having a clearance between the rack bar and a support yoke can be kept always constant when the vehicle steering apparatus is operated, which makes it possible to reduce operational friction and noise, to maintain the supporting force of the support yoke and the rack bar to be constant for a long time, and to improve a steering feeling of a driver.

A vehicle body drifting restraining device which restrains a drifting of a vehicle body, wherein: when a brake control device operation prohibition switch, which prohibits an operation of a brake control device, is in a state of prohibition, a control for restraining the drifting of the vehicle body is prohibited.

When an ECU is powered on, an overall control unit determines whether a temperature detected by a temperature sensor is lower than or equal to a predetermined temperature. When it is determined that the detected temperature is lower than or equal to the predetermined temperature, the overall control unit provides a second operation start command for operating a valve driving motor control unit in a rotation direction alternately switching mode, to the valve driving motor control unit. When the valve driving motor control unit receives the second operation start command from the overall control unit, the valve driving motor control unit starts operating in the rotation direction alternately switching mode.

An outboard motor steering system wherein an electric motor is installed inside the outboard motor and the output of the electric motor rotates a swivel shaft to steer the propeller, thereby enhancing steering feel by using an electric motor to enable highly responsive and accurate control. In addition, the configuration is simple and does not lead to an increase in number of components or weight. In another steering system wherein a first hydraulic cylinder for driving a steering system and second hydraulic cylinders for driving a power tilt-trim system are supplied hydraulic oil from the same pump, thereby making a dedicated hydraulic pump for the steering system unnecessary and thus enabling reduction of system size and weight. In still another steering system wherein the outboard motor main unit is swiveled to turn the propeller by extension / contraction of the hydraulic cylinder whose one end is attached to the outboard motor main unit and other end is attached to the boat side of the outboard motor. In a plan view taken in the gravitational direction, moreover, the hydraulic cylinder is located inside the vertical projection plane of the profile of the outboard motor main unit, so that the hydraulic cylinder never projects outside the outboard motor main unit no matter how much it extends or contracts.

The present invention relates to a rack bar supporting device for a vehicle steering apparatus. According to the present invention, a clearance between the rack bar and a support yoke can be kept always constant when the vehicle steering apparatus is operated, which makes it possible to reduce operational friction and noise, to maintain the supporting force of the support yoke and the rack bar to be constant for a long time, and to improve a steering feeling of a driver.

A steering control method controls the steering of a vehicle having a steer-by-wire steering mechanism. A steering reaction force is set that includes a restoration component for restoring a steering angle of the steering wheel to a reference angle, a viscous component corresponding to a steering angular velocity of the steering wheel, and a friction component corresponding to the steering angular velocity. An actuator is controlled to apply a rotational torque to the steering wheel for generating the steering reaction force. A turning angle of the steered wheel is controlled in accordance with the steering angle. A target travel path is set upon determining the driver is not operating the steering wheel. The actuator is controlled such that the steering angle becomes a target steering angle for causing the vehicle to travel along the target travel path to suppress the friction component of the steering reaction force.

[Problem]An object of the present invention is to provide an electric power steering apparatus that suppresses the vibration of the operating member such as the handle and improves the steering feeling due to the characteristic compensation of the assist map, without of the change of the PI-control gain in the current control section.[Means for Solving the Problem]The present invention is an electric power steering apparatus that calculates a current command value with reference to an assist map inputting a steering torque and assist-controls a steering system of a vehicle by driving a motor based on the current command value, comprising: a first compensating section provided at a front stage of the assist map; and a second compensating section provided at a rear stage of the assist map; wherein the current command value is calculated with a characteristic of which sloping increases for an absolute value of the steering torque being inputted into the first compensating section and is outputted from the second compensating section, and vibrations of operating members are suppressed.

A vehicle steering apparatus for setting a target steering reaction force to be applied to a steering wheel on the basis of a steering angle and a vehicle speed and for performing reaction force control to apply the target steering reaction force, is provided with: a steering speed specifying device for specifying a steering speed of the steering wheel; and a target steering reaction force changing device for changing magnitude of the target steering reaction force in accordance with magnitude of an absolute value of the steering speed specified by the steering speed specifying device.

A method and system for inhibiting torque steer in a vehicle equipped with steerable wheels that are power driven. The method determines a maximum engine torque limit, determines an estimated driver-desired torque, and controls the actual torque, by adjustment of the throttle angle, to be the smaller of the maximum engine torque limit and the estimated driver-desired torque. Sensors measure steering angle and transmission gear position and a calculator determines the maximum engine torque limit based upon the steering angle and transmission gear position. Further sensors measure engine speed, throttle angle, and atmospheric pressure, and a calculator estimates driver-desired torque based upon the measured engine speed, throttle angle, and atmospheric pressure. A comparator selects the lower of the maximum engine torque limit and the driver-desired engine torque and uses the selected torque to control throttle angle to inhibit torque steer.

In a controller for an electric power steering apparatus, a target value calculation element, which calculates target values of the drive currents of a motor on the basis of a detected value of the steering torque, is constituted by a first integrated circuit provided in a chip. A drive signal value calculation element, which calculates drive signal values for driving the motor on the basis of the target values calculated by the target value calculation element, detected values of the drive currents of the motor, and a detected value of the rotary position of a rotor of the motor, is constituted by a second integrated circuit provided in another chip from the chip. A driving element drives the motor in accordance with the drive signal values. The first integrated circuit is connected communicably to the second integrated circuit. The calculation cycle of the drive signal values is set to be shorter than the calculation cycle of the target values.

In an electric power steering system, a control signal output section outputs independent dual-system control signals to driver circuits that are disposed in connection with independent dual-system motor coils. The control signal output section gives high priority to the output of the control signal to the other system, when the occurrence of energization failure is detected in one system. When the energization failure occurring phase is only one phase and the value of the basic command exceeds the upper limit of the priority command, the control signal output section outputs the control signal to the driver circuit in the system where the energization failure has occurred in order to supply electric power in which the two phases other than the energization failure occurring phase are used as the energized phases on the bases of the complementary command that corresponds to the excess of the upper limit.

An electric power steering apparatus that suppresses the vibration of the operating member and improves the steering feeling due to the characteristic compensation of the assist map, without a change of a proportional and integral (PI) control gain in the current control section. The electric power steering apparatus includes a first compensating section provided at a front stage of the assist map and a second compensating section provided at a rear stage of the assist map. A current command value is calculated with a characteristic of which sloping increases for an absolute value of the steering torque being input into the first compensating section and being output from the second compensating section. Therefore, vibrations of operating members are suppressed.