Abstract: An electric power steering device includes a steering angle reference yaw rate calculation section that calculates a steering angle reference yaw rate by using a speed of a vehicle and a steering angle of a steering wheel, a torque estimation device that estimates a self-aligning torque (SAT) generated in a turning wheel of the vehicle on the basis of a measured yaw rate or the steering angle reference yaw rate, the absolute value of which is smaller, and the speed of the vehicle, and estimates a required assist torque on the basis of the estimated SAT, and an abnormality determination section that determines whether or not a steering torque sensor is abnormal. If the steering torque sensor is abnormal, an EPS control device controls drive of an assist motor using the required assist torque estimated by the torque estimation device, in place of a steering torque.

Abstract: Disclosed is a power steering apparatus including: a rack shaft that includes a rack, and moves front wheels; a steering wheel-side pinion shaft that includes a pinion meshing with steering wheel-side rack teeth of the rack shaft, and is rotated along with the steering of a steering wheel; an assistance unit-side pinion shaft that includes a pinion meshing with an assistance unit-side rack of the rack shaft, and is driven by an electric motor to rotate so as to assist the rotation of the steering wheel-side pinion shaft; and a steering angle sensor that is provided on the assistance unit-side pinion shaft, and detects a rotational angle of the assistance unit-side pinion shaft.

Abstract: An electric power steering apparatus including a steering wheel return control section that calculates a steering wheel return control current by a steering angle, the steering torque, the vehicle speed and a steering angle velocity, and drives the motor by a compensation current command value made by adding the steering wheel return control current to the current command value.

Abstract: A vehicle comprising an electric power assist steering (EPAS) system, wherein the EPAS system is configured to receive a detected value of steering wheel angle and/or steering wheel angular velocity and wherein the EPAS system is configured to improve the accuracy of the detected value of steering wheel angle and/or steering wheel angular velocity by compensating for any one or more of an angular phasing of the joint between any two linked components of the steering mechanism and the effect on steering wheel angle of the deflection across a torque sensor at least substantially due to the stiffness of that torque sensor.

Abstract: An electronic power steering apparatus for a vehicle having a steering mechanism to generate a steering assisting force includes: a steering angle sensor; a steering torque sensor; a target steering torque setting unit for setting a target steering torque based on the detected steering angle; a torque deviation computing unit for computing a torque deviation between the target steering torque and the detected steering torque; a first target current value computing unit for computing a first target current value for generating a steering assisting force by the motor based on the computed torque deviation; and a vehicle speed sensitivity adjusting unit that adjusts the first target current value, at least corresponding to a detected vehicle speed, and outputs the adjusted first current value as a second target current value. The motor control unit controls the motor to generate the steering assisting force based on the second target current value.

Abstract: A robot system includes: a robot; a three-phase inverter having a high side switch and a low side switch connected in series; a power line electrically connecting a connection point between the high side switch and the low side switch to a stator winding of a motor; a short circuit path that electrically connects at least two lines of the power line; a brake switch arranged in the short circuit path to change the short circuit path to an open state or a closed state; a break detector that detects a disconnection of the power line; and an operation part that operates the brake switch from the open state to the closed state, when the break detector detects the disconnection.

Abstract: Provided is a steering reaction force control apparatus for a vehicle including a driving support device configured to control an electric power steering device via a controller so that a steered angle of steered wheels reaches a target steered angle. When the driving support device is operating, the controller calculates a target steering spring torque based on a corrected steering angle corrected by a target steering angle for driving support control. When the magnitude of the corrected steering angle is less than a reference value, the target steering spring torque is calculated so that the magnitude of the target steering spring torque becomes larger in a case where the driving support device is operating compared with a case where the driving support device is not operating.

Abstract: An electric motor controller and methods of determining which input power line of a plurality of input power lines of a motor drive controller has been energized are provided. An electric motor controller configured to be coupled to an electric motor includes a plurality of power input lines configured to receive an alternating current (AC) input voltage from an AC power source, an energized line detection device configured to sense that a power input line has been energized by the AC power source, and configured to output an isolated signal, and a rectifier configured to convert the AC input voltage having a frequency to a direct current (DC) voltage. The controller also includes a computing device coupled downstream from the energized line detection device and configured to determine which input power line has been energized.

Abstract: An electric steering device includes an electric actuator which generates a steering assist force for a steering mechanism of a vehicle, a control unit which controls the steering assist force generated from the electric actuator based on an operation of a steering wheel by a driver, an ignition signal detection unit which detects presence or absence of an ignition signal of the vehicle, and a speed acquisition unit which acquires a running speed of the vehicle. In a case that the ignition signal is not detected and the running speed is a predetermined speed or more, the control unit reduces an upper limit of the steering assist force generated from the electric actuator so as to be smaller than an upper limit in a case that the ignition signal is detected.

Abstract: In a power steering device and a vehicle-mounted instrument, an abnormality detection accuracy of a state quantity detection means is increased. In an electric power steering device and a vehicle-mounted instrument that are each provided with a plurality of state quantity detection means, an abnormality detection for the state quantity detection means is carried out by comparing detection signals issued from the state quantity detection means provided on a redundant system, and by comparing the detection signals issued from the state quantity detection means with signals that are issued from other state quantity detecting means and calculated to be matched with the same unit as the compared detection signals, a value or close value that is possessed by the largest number of signals is set as a normal value.

Abstract: A vehicle steering device (11) is provided that performs steering of a vehicle in response to operation of a steering wheel (13) operated when the traveling direction of the vehicle is changed. The vehicle steering device (11) includes a first steering assist device having a first steering torque sensor (23), a first assist motor (51), and a first EPS control unit (37), and a second steering assist device having a second steering torque sensor (25), a second assist motor (57), and a second EPS control unit (39). The first and second EPS control units (37, 39) perform driving control of the first and second assist motors (51, 57) independently from each other. Even if either one of the two control units (37, 39) respectively controlling driving of the two assist motors (51, 57) fails into an abnormal situation, such an abnormal situation can be brought under control quickly and soundly.

Abstract: A method for controlling a vehicle driveline includes connecting an electric motor to each of respective vehicle wheels, determining from driver input a magnitude of demanded wheel torque, determining speed of each wheel, using demanded wheel torque and the respective wheel speed to determine from a power loss map a current power loss for each motor, and transmitting power from the motor having the lowest current power loss to the respective vehicle wheel.

Abstract: A method of controlling disturbances associated with electric power steering (EPS) systems maintains an original assist torque to feedback signal in the EPS, such as a column torque, and further minimizes the impact from the disturbance source to the feedback signal so that the disturbance is rejected while the original steering feel is maintained. The method further considers interaction of the rejection feature with other functions of the EPS. In one embodiment, relationships for isolating the disturbance are achieved by utilizing a combined feedback and feed-forward compensator.

Abstract: An electric power steering system includes a basic assist amount calculation section calculating a basic assist amount for assisting the manipulation of a steering wheel, and an assist compensation amount calculation section calculating an assist compensation amount for correcting the basic assist amount. The system includes an assist amount correction section calculating a corrected assist amount by correcting the basic assist amount based on the assist compensation amount, and a motor drive section driving a motor using the corrected assist amount. The assist compensation amount calculation section uses a reverse input specification that more transmits the signal components of specific frequency in road-surface input torque, to a steering wheel than in the case of using only the basic assist amount, and calculates the assist compensation amount suitable for a vehicle-state value, such as a steering torque, to suppress variation in the transmission characteristics due to variation of the vehicle-state value.

Abstract: A system for actively damping a power steering system includes a damping activation module that generates a damping activation signal based on a motor velocity signal, a t-bar torque signal, and a final motor command; a command calculation module that generates a calculated command based on the motor velocity signal and a vehicle speed signal; and a damping calculation module that generates a damping command based on the damping activation signal and the calculated command, the damping command reduces a motor velocity of a motor of the power steering system to mitigate a rack disturbance.

Abstract: A control device (50) for an electric power steering device (10) is configured to: store a basic target return speed (Vrb), which increases in magnitude as the magnitude of a steering angle (?) increases; calculate, when a steering wheel (14) is being returned to a neutral position, the basic target return speed (Vrb) based on an actual steering angle (Step 10); calculate a transitional target return speed (Vtrt), which gradually increases in magnitude and gradually approaches the basic target return speed as the magnitude of the actual steering wheel decreases; and control, when the magnitude of a difference between the basic target return speed and the transitional target return speed is more than a reference value, a steering assist torque so that a return speed reaches the transitional target return speed (Step 20 to Step 160).

Abstract: A steering system includes a steering mechanism, a motor that is a source of an assist force, and a battery that supplies a voltage to the motor. The system includes a voltage sensor that detects a power supply voltage, a steering sensor that detects a steering angle, and a motor control signal generation circuit that calculates a q-axis voltage command value to allow the motor to generate the assist force and that generates a motor control signal based on the q-axis voltage command value. The system includes a steering-angular-velocity limiting circuit that calculates a compensation amount for compensation for the q-axis voltage command value and that derives the compensation amount by calculating a power supply compensation component based on the power supply voltage when the absolute value of the steering angle is equal to or larger than a predetermined steering angle close to a maximum steering angle.

Abstract: A vehicle comprising a closed-loop electric power assisted steering (EPAS) system comprising a control unit configured to compute an artificial friction component and to compute a desired reference torque (?ref) incorporating the artificial friction component, wherein the artificial friction component is dependent upon steering wheel angle (?).

Abstract: [Problem] An object of the present invention is to provide an electric power steering apparatus that is capable of positively returning a steering wheel to a neutral point in such a running state as to return to a going straight state by calculating a return control current corresponding to a steering angle and a steering speed and compensating a current command value.

Abstract: A parking assist system parks a vehicle at a target parking position by automatically steering an EPS. The parking assist system includes a acquiring unit configured to acquire the position of the vehicle, a position determining unit configured to determine the target parking position, a generating unit configured to generate a path from the position of the vehicle to the target parking position, a detecting unit configured to detect the temperature of the EPS, and a assist unit configured to automatically steer the vehicle so as to move along the path generated by the generating unit. The generating unit generates a path in which a degree of stationary steering by which the vehicle is steered in a state where the vehicle stops is small when the temperature of the EPS is high, compared with when the temperature of the EPS is low.

Abstract: Output signals of a torque sensor include a first output signal used in an assist control and a second output signal used in controls other than the assist control. An adjusting device of an electric power steering device includes an input torque meter for measuring an input torque applied to the input shaft, an output torque meter for measuring an output torque output by the steering mechanism, and a sensor output corrector for correcting an output signal of the torque sensor. The sensor output corrector corrects the first output signal so that a relationship between the input torque measured by the input torque meter and the output torque measured by the output torque meter becomes an ideal characteristic set in advance, and corrects the second output signal so that an input torque detected by the torque sensor coincides with the input torque measured by the input torque meter.

Abstract: A driving device for motors for drive wheels of a vehicle includes a plurality of in-wheel motor assemblies and motor drivers. The motor drivers include a smoothing circuit, an inverter unit to convert the direct current power, inputted through the smoothing circuit, into a three phase alternating current power, an inverter control unit for controlling the inverter unit, and a cooler for cooling the inverter unit. The plurality of the motor drivers are disposed within a single common casing and the plurality of the motor drivers share the smoothing circuit. The inverter control unit of the plurality of the motor drivers is of a control type capable of driving the driving element of the inverter unit according to the PWM scheme and the plurality of the motor drivers have equal cycles of PWM relative to each other and are configured to displace ON and OFF timings of the driving element.

Abstract: A control unit for an electric power steering apparatus that controls a motor based on a current command value (2) calculated based on a current command value (1) due to steering torque generated on a steering shaft and a current detection value of the motor providing a steering mechanism with a steering assist force. The apparatus includes an SAT estimating section that inputs a motor angular velocity, a motor angular acceleration, the current command value (1) and the steering torque, and estimates a self-aligning torque (SAT) or measures by a sensor; and a feedback section that processes the estimated SAT value and outputs an SAT compensation value. The feedback section comprises a BPF, a dead band section, a steering torque sensitive gain section and a vehicle velocity sensitive gain section. The current command value (2) is obtained by adding the SAT compensation value to the current command value (1).

Abstract: A multi-phase motor control apparatus that reduces the occurrence of the vibrations and the noises by setting the shift amount per time more finely after realizing a reduction in processing ability of a CPU by using a one-shunt type current detection circuit and an electric power steering apparatus using the same. The apparatus includes a PWM-signal generating section that generates plural second each-phase PWM-signals within two control periods based on the current estimation value and the carrier signal, and in a case that a phase shift amount of a predetermined phase in a just before control period is zero and a phase shift amount of a predetermined phase in a present control period is not zero, the phase shift control section gradually increases the phase shift amount from zero in the present control period and a next control period, and uses the second each-phase PWM-signals in the next control period.

Abstract: A core of a worm wheel has an axial end surface formed with a first annular recess, another axial end surface formed with a second annular recess, and a third annular recess formed in a radially outer region of the first annular recess. A rim portion has a first inner circumferential portion fixed to the first annular recess, a second inner circumferential portion fixed to the second annular recess, and a protrusion engaged with the third annular recess.

Abstract: A torque steering angle sensor is provided. The sensor includes a ring magnet with magnetic poles, magnetic path forming members to vary in location relative to the magnetic poles depending on torsion of a torsion bar, one pair of magnetic flux collecting rings for the magnetic path forming members, a first detecting element to detect a magnetic field between the flux collecting rings, a second detecting element to receive a magnetic field from the ring magnet, a slide magnet for producing a magnetic field in a different direction from that of the magnetic field of the ring magnet in the second detecting element, and a sliding mechanism to move the slide magnet toward or apart from the second detecting element with rotation of a rotary member of an electrically assisted power steering device. The second detecting element detects the magnetic fields received from the ring magnet and the slide magnet.

Abstract: A method for supplying power to an electrically assisted steering system is described. In one example, the method adjusts alternator field current to increase energy supplied to the electrically assisted steering system in response to an automatic engine stop request. The method may improve operation of the electrically assisted steering system.

Abstract: There is provided a fail-safe apparatus for an inverter that can suppress the voltage of a DC power source from rising when the voltage of the DC power source becomes excessive, due to an abnormality caused in an inverter that performs driving and electric-power generation by use of a synchronous motor in which a permanent magnet is utilized as a magnetic-field magnet. The fail-safe apparatus for the inverter includes an excessive voltage detection circuit for detecting a state of excessive voltage while monitoring the voltage of the DC power source of the inverter and a drive switching circuit for switching a driving method for a semiconductor switching device between three-phase PWM driving and three-phase short-circuiting driving in accordance with the state of an excessive voltage detection circuit.

Abstract: An excessive torque restricting mechanism restricts a magnitude of a torque which is to be transmitted from a steering shaft to a connecting mechanism including a tie rod, a magnitude of a torque which is to be transmitted from a left shock absorbing mechanism to the connecting mechanism, and a magnitude of a torque which is to be transmitted from a right shock absorbing mechanism to the connecting mechanism.

Abstract: A system is described that includes a first portion including one or more components configured to implement one or more safety functions of an application. The system further includes, a second, different portion comprising one or more different components configured to activate a safety path in response to a detection of a voltage overstress in the first portion. The system further includes a third, different portion comprising one or more different components configured to electrically couple the first portion to the second portion and to prevent the voltage overstress from propagating from the first portion to the second portion.

Abstract: A core of a worm wheel has an axial end surface formed with a first annular recess nad and another axial end surface formed with a second annular recess. An outer circumferential wall surface of a radially outer region of the second annular recess has a tapered surface extending from a bottom surface of the second annular recess to form an obtuse angle relative to the bottom surface, and a third annular recess formed radially outside the tapered surface. A cross-section of the third annular recess is a right-angled triangle having, as two sides, a surface parallel to the bottom surface of the second annular recess and a surface perpendicular to the bottom surface of the second annular recess. A rim portion has a first inner circumferential portion fixed to the first annular recess and a second inner circumferential portion fixed to the second annular recess.

Abstract: In a vehicle steering that sets a target steering reaction force to be applied to a steering wheel on the basis of a steering angle of the steering wheel and that applies the target steering reaction force to the steering wheel; the target steering reaction force is set so that the target steering reaction force changes on the basis of whether a steering mode of the steering wheel is turn steering in which the absolute value of a steered angle of a steered wheel is increased or return steering in which the absolute value of the steered angle is reduced; and the set target steering reaction force is applied to the steering wheel.

Abstract: A method of adjusting friction of an MDPS unit may include detecting road surface conditions of a road on which a vehicle travels; classifying the road on which the vehicle travels into a normal road, a low frictional road, a road having a first uneven road surface, and a road having a second uneven road surface; and reducing friction of the MDPS unit of the vehicle when the road on which the vehicle travels is determined as the road having the first uneven road surface.

Abstract: An electric power steering system for a vehicle works to determine an assist command based on steering torque to produce assist torque through an electric motor for assisting in turning a steering wheel of the vehicle, also determines a tracking command for producing automatic steering torque which brings a value of a given physical quantity associated with steering of the vehicle into agreement a target value, and calculates a vibration correction command for use in producing vibration correction torque which suppresses vibration of the steering torque which arises from output of the torque from the electric motor based on a transfer characteristic of transmission of the output of torque from the electric motor as a part of the steering torque through the steering mechanism. A motor driver works to actuate the electric motor based on the sum of the assist command, the tracking command, and the vibration correction command.

Abstract: An adjusting apparatus for an electric power steering device includes a steering mechanism converting an input torque into a steering force and transmitting the steering force to wheels, a torque sensor outputting a torque detection signal according to an input torque, an electric motor applying a steering assist torque according to a torque detection signal output from the sensor, a sensor circuit changing output characteristics of the sensor, an actuator applying an input torque to the steering mechanism, a steering force meter actuating the motor via the sensor according to an input torque and measuring a steering force output by the steering mechanism, and a sensor output adjuster adjusting the output characteristic of the sensor circuit to approximate a steering force measured by the meter to an ideal value set in advance according to a deviation amount calculated based on a difference between the steering force and the ideal value.

Abstract: A method for monitoring an electrically-powered torque machine configured to generate torque in a hybrid powertrain system includes monitoring signal outputs of a resolver configured to monitor rotational position of the torque machine. Upon detecting a fault warning state associated with the signal outputs of the resolver, a motor torque capacity of the torque machine is derated. Upon a clearing of the fault warning state, a torque ramp-up state to increase the motor torque capacity of the torque machine is executed. Notice of an incidence of a fault associated with the signal outputs of the resolver is provided only when the motor torque capacity fails to achieve a threshold motor torque capacity within a threshold recovery time period while executing the torque ramp-up state.

Abstract: A core of a worm wheel has an axial end surface formed with a first annular recess and another axial end surface formed with a second annular recess. A rim portion has a first inner circumferential portion fixed to the first annular recess and a second inner circumferential portion fixed to the second annular recess. An outer circumferential wall surface of the second annular recess extends from a bottom surface of the second annular recess so as to be perpendicular to the bottom surface. A depth of the second annular recess is at least 0.1 mm but not deeper than half of a gate thickness.

Abstract: A controller of a steering apparatus includes a calculating unit that calculates a correction assistance quantity based on a steering angular velocity coefficient and a torque coefficient, a steering angular velocity coefficient setting unit that sets the steering angular velocity coefficient depending on a steering angular velocity and that sets the steering angular velocity coefficient to become larger as a feedback quantity of a negative feedback unit becomes larger, and a torque coefficient setting unit that sets the torque coefficient depending on a steering torque and that sets the torque coefficient to become larger as the feedback quantity of the negative feedback unit becomes larger. The feedback quantity of the torque coefficient setting unit when the steering torque is in a predetermined high-frequency range is larger than the feedback quantity of the steering angular velocity coefficient setting unit when the steering angular velocity is in a predetermined high-frequency range.

Abstract: A control apparatus controls a motor of an electric power steering system including: an input shaft connected to a steering member; a column shaft connected to the input shaft; a turning device that includes a rack and pinion mechanism, and turns a wheel; and the motor. The control apparatus includes a reliability computation portion that computes a reliability according to an abnormality detection state regarding at least one of a current sensor, a torque sensor, and a rotational angle sensor; a steering-shaft load estimation portion that estimates a steering shaft load using a current corresponding value, a torque corresponding value, and a rotational angle corresponding value; and a weight changing portion that changes a weighting of the current corresponding value, the torque corresponding value, or the rotational angle corresponding value according to the reliability.

Abstract: A vehicle steering system can keep the comfort of steering feeling for a driver, even in a situation, such as traveling on a cant road or in a crosswind, where a unidirectional-drift behavior of a vehicle occurs, and includes an electric motor, a steering angle sensor, a steering torque sensor, and an EPS_ECU that controls driving power of the electric motor, when the vehicle is traveling straight, based on vehicle information including a steering torque and a steering angle, to perform a control for applying an assist torque to a steering system. The EPS_ECU includes an integrating unit for calculating an integrated torque value obtained by integrating the steering torque, and a steering effort assist controlling unit for performing an anti-unidirectional-drift control over the driving power of the electric motor, when the integrated torque value exceeds the threshold value, so as to cancel the unidirectional-drift behavior of the vehicle.

Abstract: The present invention relates to a method of preventing over stroke in a rear-wheel steering system for a vehicle, and more particularly, to a method of preventing the over stroke of a lead screw using a linear sensor moving together with the lead screw in a rear-wheel steering system. In detail, there is provided a method of preventing over stroke in a rear-wheel steering system, including determining whether a linear sensor which moves in conjunction with a lead screw enters preliminary sections A of a stroke section a and restricting the movement of the lead screw when the linear sensor enters the preliminary sections A.

Abstract: An electric power steering system including: a torque sensor; a steering angle sensor configured to detect a steering angle value of a steering wheel; a motor position sensor configured to detect a motor rotation angle value which is a rotated angle of a driving shaft of an electric motor; and an electronic control unit configured, when the torque sensor is normal, to generate a first steering assist current for controlling a driving force of the electric motor using the steering torque value, and when the torque sensor fails, to estimate a target motor angular velocity of the electric motor using the steering angle value and the motor rotation angle value and to generate a second steering assist current so as to cause a current motor angular velocity of the electric motor to converge to the target motor angular velocity.

Abstract: A drive controller and a method for operating a drive controller having a converter with a DC link circuit, includes measuring during operation phase currents generated by the converter; forming from the measured phase currents a current vector in a first coordinate system; rotating, with a first transformation angle and with a first rate of change, the current vector into a second coordinate system to generate a resulting current vector; supplying the resulting current vector to a regulator to generate a resulting voltage vector at an output of the regulator; rotating, with the first transformation angle or with a second transformation angle rotating at the first rate of change, the resulting voltage vector back into the first coordinate system to generate a resulting back-transformed voltage vector; and using the resulting back-transformed voltage vector as an influencing variable in addition to U/f control or vector regulation for controlling the converter.

Abstract: A vehicle includes an engine configured to auto stop and auto start. The vehicle includes an active front steering system with an electric actuator. A controller operates the electric actuator at a current limit that is less than a requested current of the electric actuator in response to a request to change a steering ratio by an amount that results in the requested current being greater than the current limit during an engine auto stop event. The current limit may decrease from the requested current to a predetermined limit after transitioning to the engine auto stop event. The current limit may increase from the predetermined limit to the requested current after transitioning from the engine auto stop event.

Abstract: Maneuverability and stability of a suspension unit for a vehicle are improved. A vehicle includes: a steer-by-wire system detecting a displacement of a steering wheel and displacing a steering rack steering steerable wheels on a basis of a detection result of the displacement and a suspension unit suspending the steerable wheels, the suspension unit including: wheel hub mechanisms, each wheel hub mechanism supporting a tire wheel on which a tire is attached, and a plurality of link members supporting the wheel hub mechanisms on the vehicle body; and a kingpin axis passing through an upper pivot point of the link members and lower pivot point of the link members being set to pass through a road surface contact area of the tire at a neutral position of the steering wheel.

Abstract: For compensation for loss of a steering assist force due to friction of a steering mechanism, when calculating a friction correction value for the compensation, in an electronic control unit 6, a static friction and a kinetic friction are distinguished, and the calculation is made by combining the static friction correction value Sf and the kinetic friction correction value Kf according to each friction. It is therefore possible to make a proper friction loss compensation according to type of the friction.

Abstract: An electric power steering device includes a basic return command value calculation unit configured to calculate a basic return command value in a direction returning the steering wheel to a neutral position, on the basis of detection results of a steering angle detector detecting a steering angle of the steering wheel, a first correction gain calculation unit configured to calculate a first correction gain correcting the basic return command value, on the basis of detection results of a vehicle speed detector detecting vehicle speed, and a second correction gain calculation unit configured to calculate a second correction gain correcting the basic return command value, on the basis of a change amount of the steering torque detected by the torque sensor. The basic return command value is corrected by the first and second correction gains so as to calculate a return command value. The return command value is added to the assist command value so as to drive the electric motor.

Abstract: A system or method for steering support for a vehicle with a start-stop system is configured to temporarily switch off a running internal combustion engine at the beginning of a stop phase and to restart the internal combustion engine at the end of the stop phase. An electric motor of the steering support is operated with accumulated electric current during the stop phase. Consumption of the accumulated current is monitored from the beginning of the stop phase with future consumption of current by the electric motor estimated based on consumption during previous stop phases. The steering support is configured so that supply of the accumulated current to the electric motor during the stop phase can be regulated as required on the basis of the estimated future consumption of accumulated current by the electric motor.

Abstract: An electric power steering system is provided which can take an abnormality countermeasure without being affected by a torque abnormality signal and without giving an uncomfortable feeling to a driver when torque abnormality occurs. Abnormality of a steering assist command value is detected by employing a dual detection configuration of a main ECU clip (34) and a sub ECU interlock (62). When abnormality of a steering torque Ti detected by a torque sensor (3) is detected, input values to the main ECU clip (34) and the sub ECU interlock (62) are switched from the steering torque Ti detected by the torque sensor (3) to an alternative torque value. Here, the alternative torque value employs a previous torque value calculated based upon the normal steering torque Ti detected by the torque sensor (3) when the abnormality of the steering torque Ti detected by the torque sensor (3) is not detected.

Abstract: A power steering apparatus has a first characteristic which is a characteristic of a command signal with respect to steering torque and a second characteristic which is a characteristic different from the first characteristic. When switching is to be made to a characteristic selected from between the first and second characteristics, an interpolation characteristic intermediate between the first and second characteristics is calculated so that the characteristic used before switching of the characteristics gradually approaches the characteristic to be used after the switching, and a characteristic switching time for switching between the first and second characteristics is variably controlled in accordance with the steering torque.