Abstract: A system for providing steering torque assistance to an electrically-powered steering apparatus comprises a torque assistance motor coupled to the steering apparatus. A steering controller is configured to cause the torque assistance motor to apply a commanded level of steering torque assistance to the steering apparatus. The steering controller is configured to determine the commanded level of steering torque assistance based on a product of a scheduled level of steering torque assistance and a torque assistance scale factor, wherein the scheduled level of steering torque assistance is determined from a scheduled torque assistance characteristic having a nominal assist. The steering controller is configured to determine a scaled assist based on feedback from one or more safety sensors; and the torque assistance scale factor is determined as a ratio of the scaled assist and the nominal assist.

Abstract: An electric power steering system includes a motor that applies assist force to a steering system, and updates a motor resistance (Rm) that is a value indicating a resistance of the motor. Specifically, the motor resistance (Rm) is updated on the basis of the fact that an induced voltage (EX) of the motor is smaller than a first determination value (GA). In addition, when the induced voltage (EX) is smaller than or equal to a second determination value (GB), a divided value that is obtained by dividing a motor voltage (Vm) by a motor current (Im) is set as a new motor resistance (Rm).

Abstract: In an electric power steering system, an ECU 11 includes two independent microcomputers 17a, 17b that serve as motor control signal generators, and the microcomputers 17a, 17b perform the same current feedback computation. Switching arms 20a, 20b that constitute a driving circuit 18 operate independently of each other, based on motor control signals generated by the corresponding microcomputers 17a, 17b. Each of the microcomputers 17a, 17b determines whether an absolute value of a current deviation of an actual current I (I1, I2) from a current command value exceeds a predetermined threshold value. If the current deviation exceeds the threshold value, it is determined that an abnormality occurs in the system.

Abstract: A vehicle steering control apparatus includes an actuator to vary a steering gear ratio of a vehicle wheel steer angle of a steerable wheel to a steering wheel angle. A controller controls the actuator to produce an actuator torque in a steering direction at a start of a driver's steering operation.

Abstract: A system and method for controlling a vehicle steering system, comprising receiving at least one signal corresponding to one or more of a lateral acceleration, a longitudinal acceleration, a vertical acceleration, a suspension travel, and a vehicle speed, calculating or determining an optimum steering rack travel from the at least one signal, and limiting travel of a steering rack of the vehicle based on the optimum steering rack travel.

Abstract: An assist control portion, upon detecting source power supply abnormality of a main electric power source, switches the characteristic of an assist map in which the steering torque and the target current are related to each other from an original assist characteristic to an abnormality-time assist characteristic. Therefore, the steering handle operation suddenly becomes heavy, thereby causing the driver to be aware of the abnormality. After that, the abnormality-time assist characteristic is altered so that the assist force relative to the steering torque further decline in accordance with declines in the actual amount of charge of the subsidiary electric power source declines. Therefore, the steering handle operation gradually becomes heavier, thereby causing the driver to anticipate that the abnormality is further progressing.

Abstract: A power steering assist system for a hand-steered pallet truck includes a joint assembly having a pivot joint, handle biasing mechanism, and a torque sensing arrangement. The pivot joint includes a pair of needle bearings and pivot pin disposed within a pivot block that provides a flexible connection between a handle and a tiller arm. The handle biasing mechanism includes a cantilevered beam spring and two cam rollers that resists an operator steering force applied to the handle and further, centers the handle with respect to the tiller arm after the force is released. The torque sensing arrangement includes a magnet and a non-contact magnetoresistive (MR) sensor that measures movement of the handle relative to the tiller arm which is used to determine operator steering intent, i.e., the amount of steering force applied to the handle. The MR sensor provides accurate torque measurements regardless of the angle of the tiller arm.

Abstract: Provided is a rear wheel toe angle control system that can prevent the impairment of the tracking performance of the electric actuator and enable the rear wheel toe angle control system to ensure the stability of the vehicle even when the electric actuator for steering the rear wheel according to the operating condition of the vehicle is subjected to an axial force. An ECU (12) serving as a rear wheel toe angle control unit for variably controlling the rear wheel toe angle (?r) of the motor vehicle (V) by using an electric actuator (11) is provided with a duty ratio correcting unit (25) that corrects the target duty ratio (Dtgt) for achieving the target rear wheel toe angle (?rtgt) according to the load condition of the electric actuator (11) that depends on the lateral acceleration (Gy) of the motor vehicle (V).

Abstract: A road surface frictional coefficient estimating apparatus has a device for determining a first estimated value of a yaw moment Mnsp_estm generated at an NSP of a vehicle due to the resultant force of road surface reaction forces acting on each wheel by using, for example, a frictional coefficient estimated value that has been determined, and a device for determining a second estimated value of a yaw moment Mnsp_sens generated at the NSP from the observed value of motional state amounts defining an inertial force moment at the NSP. The increasing/decreasing manipulated variable of the frictional coefficient estimated value is sequentially determined on an error (Mnsp_sens?Mnsp_estm) such that the error is converged to zero, and the road surface frictional coefficient is updated on the basis of the increasing/decreasing manipulated variable.

Abstract: A steering device for adjusting a wheel steering angle of a wheel of a motor vehicle is disclosed, which steering device has just one central wheel guide member for changing the wheel steering angle of the wheel and not a plurality of wheel guide members. The length of the wheel guide member can be adjusted, wherein a change in length of the central wheel guide member brings about a change in the wheel steering angle of the wheel.

Abstract: In an electric power steering apparatus, a worm gear is structured such that a leading end of a leading end shaft of the worm gear is always pressed and supported by a part in a peripheral direction of a diameter enlarged inner diameter portion of a collar which is urged by an elastically urging body, and is always urged toward a side coming close to a center shaft of a worm wheel.

Abstract: The method consists of, when the instantaneous speed of the vehicle is greater than a pre-determined threshold: identifying that the vehicle travels in a straight line without torque exerted on the steering wheel; if the prior condition is met, determining an average residual torque for the steering wheel by calculating a sliding scale of measures of torque on the steering wheel; calculating a correction, if the average residual torque on the steering wheel is greater than a pre-determined minimum torque, which is proportional to the average residual torque to be applied to the torque measures on the steering wheel; calculating effective correction limited in terms of the speed of variation and amplitude in relation to the correction applied to the measures of torque on the steering wheel, said corrected measures being subsequently treated by the electronic calculator in order to control the electronic booster motor.

Abstract: A steering angle detection device includes: a shaft angle detector that detects a rotation angle of a shaft that transmits a rotation operation of a steering member to a steering mechanism; a motor angle detector that detects a rotation angle of a motor that applies a steering assist force to the steering mechanism; a steering angle calculation unit that calculates a steering angle on the basis of a combination of the rotation angle detected by the motor angle detector and the rotation angle detected by the shaft angle detector, and a temperature detector that detects an ambient temperature of the steering mechanism, wherein the steering angle calculation unit corrects the rotation angle detected by the motor angle detector or the shaft angle detector on the basis of the ambient temperature detected by the temperature detector and uses the corrected rotation angle to calculate the steering angle.

Abstract: A vehicle steering apparatus that can prevent a large returning torque from acting when a steering wheel is turned. Through processing of an assist control program, rotational torque (assist torque) of an electric motor is calculated by adding returning torque g·Trto to turning torque Tc (in actuality, subtracting the returning torque g·Trto from the turning torque Tc). The electric motor is driven and controlled in accordance with the calculated assist torque. When the steering torque is large, the calculated returning torque gain g decreases, and therefore, the returning torque g·Trto decreases or becomes zero. With this control, the greater the force (torque) required to operate the steering wheel, the smaller the influence of the returning torque, and steering feel at the time of turning the steering wheel is improved.

Abstract: A steering wheel angle detection system having a steering wheel angle sensor, a generator and a controller memory such that when a vehicle ignition is powered off, movement of a steering wheel generates electricity and allows a steering wheel angle sensor to detect the change in steering wheel angle. The change, or an indicator, is stored in non-volatile RAM until a time in which the ignition is powered-on. The generator may be a generator dedicated to the steering wheel angle sensor or it may be an electric motor that is part of an electrically assisted power steering system.

Abstract: A vehicle steering apparatus 1 includes a variable gear ratio actuator 7, an IFS ECU 8, which controls the actuator 7, an EPS actuator 17, and an EPS ECU 18, which controls the EPS actuator 17. The variable gear ratio actuator 7 varies the transmission ratio between a steering wheel and steered wheels. The EPS actuator 17 applies an assist force that assists a steering operation. A microcomputer 43 of the EPS actuator 17 increases an inertia compensation current command Iti* (Iti**), which is a compensation component based on the differential value of a steering torque, during actuation of the variable gear ratio actuator 7, that is, when an ACT angle ?ta is changed.

Abstract: The present invention provides a rear wheel toe angle variable control system-equipped vehicle that is capable of assisting the steering of the front wheels by a power steering system mounted therein without deteriorating the steering feeling experienced by the vehicle operator even when the rear wheels have been steered.

Abstract: In a configuration in which a control is performed for actuating the steering cylinder 17 so that the steering angle of the front wheel 11a (steering wheel), which is detected by the steering angle detector 62, becomes a target steering angle which is set in accordance with an operational state of the steering dial 42, the target steering angle of the front wheel 11a (steering wheel), which is set in accordance with an operational state of the steering dial 42, is compared with a detected steering angle of the front wheel 11a, which is detected by the steering detector 62, and when the difference between the target steering angle and the detected steering angle is a predetermined value or higher, the traveling speed of the vehicle 10 is regulated so that the traveling speed of the vehicle 10 becomes a predetermined speed or lower.

Abstract: An alignment changing control device that includes: a motor drive section which adjusts electrical power supplied to a motor of the electric actuator according to an operation command and, when receiving an operation inhibiting signal, limits or stops supplying the electrical power to the motor; a motor temperature estimating section for calculating an estimated temperature of the motor from at least a current supplied to the motor, an outside air temperature and a vehicle speed, based on heat balance relationship; and a comparator which transmits the operation inhibiting signal to the motor drive section when the estimated temperature of the motor calculated by the motor temperature estimating section is higher than a predetermined temperature, which is equal to or lower than an operation allowable temperature of the motor.

Abstract: A variable toe angle control system for a vehicle that can be incorporated with a fail-safe mechanism. When a fault of the system is detected, at least one of toe-angle actuators is actuated to make toe angles of two wheels agree with each other. When one of the wheels has become fixed in position without regard to a control signal supplied to the corresponding actuator, the actuator for the other wheel is actuated so as to make the toe angles of the two wheels equal to each other. When at least one toe-angle sensor is found faulty, the actuators are both actuated until the actuators reach positions corresponding to stoppers. When information for determining target values of the toe angles of the right and left wheels is found faulty, the actuators are both actuated until the actuators reach positions corresponding to prescribed reference toe positions.

Abstract: A steering apparatus includes an axle housing rotatably supporting a wheel hub on which a steered road wheel is installed, and a lower suspension-system control arm adapted to be oscillatingly supported at one end on a vehicle body and having a turning portion provided at the other end for pivotably supporting the axle housing by the turning portion. An electric motor is installed on the lower arm for turning the axle housing by a driving force produced by the motor. A rotation axis of the motor and a pivot of the axle housing are arranged to be offset from each other.

Abstract: A steering apparatus (10) for turning steerable wheels of a vehicle in response to rotation of a vehicle steering wheel (12) comprises a first assembly (16), a second assembly (26), and a mechanism (108). The first assembly is operatively coupled to the steering wheel and includes components (18, 22) for monitoring applied torque and angular rotation of the steering wheel. The second assembly includes a steering gear (34) and components (28, 30) for actuating the steering gear in response to the monitored rotation. The mechanism, when in a first mode of operation provides a mechanical connection between the steering wheel and the steering gear. The mechanism when in the second mode of operation, providing a mechanical connection between the steering wheel and the steering gear sufficient to enable manual actuation of the steering gear and permit actuation of the steering gear in response to the monitored steering wheel rotation.

Abstract: A vehicle steering apparatus for improving steering feel when changing the angle of a steered wheel with a motor. An IFS torque compensation unit includes an oversteer IFS torque compensation gain calculation unit, which obtains a larger IFS torque compensation gain as a control target element increases during oversteer control. When an oversteer state occurs, the IFS torque compensation control unit outputs a corrected gain, which is based on the IFS torque compensation gain.

Abstract: A torque control element for a steering system in a motor vehicle, and such a steering system are provided. The torque control element includes at least two electrical units, each of the electrical units being assigned a separate power supply unit, connected via at least one fuse.

Abstract: An electric power steering apparatus is provided for suppressing the effect on the steering wheel of external interference inputted from the tie rod. The apparatus includes first and second output units for outputting first and second control amounts in accordance with the outputted torque signal, except in a dead zone thereof, respectively. The apparatus also includes gain data output units for, when the torque signal, a steering angular velocity, and a vehicle speed are within predetermined ranges, outputting gain data respectively. Steering operation is assisted by an electric motor driven on the basis of the first and second control amounts and the gain data, which afford a control signal to the motor.

Abstract: An electric power steering device that can estimate an ambient temperature and apply current limiting without using ambient temperature detecting means is provided. The electric power steering device includes a motor that supplements the driver's steering force, a controller that determines and controls the quantity of current passed to the motor, and vehicle speed detecting means. The electric power steering device includes ambient temperature estimating means provided with a vehicle speed signal input from the vehicle speed detecting means and limits the quantity of current passed to the motor according to an output from the ambient temperature estimating means.

Abstract: In a power steering device employing a hydraulic power cylinder, a motor-driven pump, and a driving power source for the motor, a power steering control system is configured to electrically connected to at least the motor and the power source for controlling a driving state of the motor and a power source voltage of the power source. The power steering control system includes a motor control circuit that generates a motor driving signal, whose command signal value is determined based on a steering assist force applied through the power cylinder to steered road wheels, a booster circuit that boosts the power source voltage, a motor angular acceleration detection circuit that detects or estimates a motor angular acceleration, and a booster-circuit control circuit that controls, responsively to the motor angular acceleration, switching between operating and non-operating states of the booster circuit.

Abstract: A steering apparatus for an automotive vehicle is provided with an electric drive unit that varies a steering ratio between a road wheel angle and a steering wheel angle of the vehicle, a temperature sensor that detects a temperature of the electric drive unit, and a control unit including a steering ratio characteristic setting block that sets a characteristic of the steering ratio including a steering gain and a steering response rate in accordance with an operating state of the vehicle and, when the temperature of the electric drive unit exceeds a first temperature threshold, adjusts the steering response rate in such a manner that the steering response rate comes closer to a base steering response rate level as the temperature of the electric drive unit becomes increased and a drive block that drives the electric drive unit to vary the steering ratio according to the steering ratio characteristic.

Abstract: An electric motor control strategy includes using a low resolution position sensor that provides a square wave output signal. The position sensor information is converted into sinusoidal commutation signals for motor control that reduces torque ripple. In one disclosed example, square wave commutation is used at low motor speeds and a controller switches to sinusoidal commutation once a selected threshold speed of the motor is reached. In another disclosed example, sinusoidal commutation is used at all motor speeds with two different techniques for converting the square wave sensor signal into a sinusoidal commutation signal, depending on the motor speed.

Abstract: In vehicular driving control apparatus and method, a steering assistance force provided for steerable road wheels of the vehicle in a direction at which a sideslip angle is decreased when a vehicular sideslip angle which is a difference between a forwarding direction of the vehicle and a steering direction of a steering wheel of the vehicle is detected and a vehicular oversteer state is detected, and thereafter, each of road wheels of the vehicle is controlled to decrease the sideslip angle when the steering assistance force is provided in a direction at which the vehicular sideslip angle is decreased and when the sideslip angle is equal to or larger than a predetermined value.

Abstract: A steering control device for a vehicle includes a first adjustment value determination means for determining a first adjustment value of a value corresponding to a wheel steering angle based on an actual value and a target value of turning state quantity, the first adjustment value is a value directing to approximate the actual value to the target value, and a steering control means for adjusting the wheel steering angle by modifying the value corresponding to the wheel steering angle based on the first adjustment value, wherein the first adjustment value determination means includes an index value obtaining means for obtaining an index value indicating a probability of an occurrence of a side-slip of a wheel and a regulation means for regulating the first adjustment value so that the greater the probability of the occurrence of the side-slip is, the smaller the first adjustment value is set to be.

Abstract: It is an object of the present invention to provide a control unit for an electric power steering apparatus for accurately detecting an abnormality of a steering angle sensor without forming the steering angle sensor as a double system or using an expensive position detection sensor. The object is achieved by calculating a relative steering angle by using inexpensive position detection sensors disposed at a motor of the electric power steering apparatus to output binary values and comparing a change amount of an absolute steering angle detected by the steering angle sensor and a change amount of the calculated relative steering angle with each other to thereby detect the abnormality of the steering angle sensor.

Abstract: A steering apparatus includes an axle housing rotatably supporting a wheel hub on which a steered road wheel is installed, and a lower suspension-system control arm adapted to be oscillatingly supported at one end on a vehicle body and having a turning portion provided at the other end for pivotably supporting the axle housing by the turning portion. An electric motor is installed on the lower arm for turning the axle housing by a driving force produced by the motor. A rotation axis of the motor and a pivot of the axle housing are arranged to be offset from each other.

Abstract: In a method for ensuring safe tire emergency running operation in a motor vehicle that is equipped with tires that have emergency running properties when the tire pressure is greatly reduced or absent altogether, a device is provided for detecting an emergency running mode of the motor vehicle. The device for limiting the driving speed limits the driving speed of the motor vehicle whenever emergency running is detected.

Abstract: A vehicle is provided having a steering system for selectively operating the vehicle in a zero-steer configuration. The system includes a forward steering assembly coupled to a steering wheel and a forward set of wheels. The forward steering assembly is arranged to receive an input from the steering wheel and includes a selectively actuateable forward motorized mechanism. A rear steering assembly is coupled to a rear set of wheels and includes a rearward motorized mechanism. Upon selective activation, the forward motorized mechanism is arranged to engage the forward steering assembly and rotate the forward set of wheels toward a centerline of the vehicle and the rearward motorized mechanism is arranged to engage the rearward steering assembly and rotate the rearward set of wheels toward the vehicle centerline such that the wheels are positioned to allow the vehicle to turn about a central point of the vehicle in a zero-steer configuration.

Abstract: An electric assisted steering system for a motor driven road vehicle, having assist torque signal generating means which generates an assist torque signal for the steering system in response to the driver's applied torque and sensed vehicle speed to reduce the driver's steering effort. A yaw rate haptic torque is generated which is based upon vehicle rate error and is arranged to be added to the torque assist signal such that, when the yaw rate error builds up corresponding to increasing steering instability (e.g. understeer or oversteer) of the vehicle, the haptic torque added to the torque assist signal reduces the effective road reaction feedback sensed by the driver in advance of any actual vehicle stability loss whereby to allow the driver to correct appropriately in good time before terminal steering instability is reached.

Abstract: An electric assisted steering system for a motor driven road vehicle, having assist torque signal generating means which generates an assist torque signal for the steering system in response to the driver's applied torque and sensed vehicle speed to reduce the driver's steering effort. A yaw rate haptic torque is generated which is based upon vehicle rate error and is arranged to be added to the torque assist signal such that, when the yaw rate error builds up corresponding to increasing steering instability (e.g. understeer or oversteer) of the vehicle, the haptic torque added to the torque assist signal reduces the effective road reaction feedback sensed by the driver in advance of any actual vehicle stability loss whereby to allow the driver to correct appropriately in good time before terminal steering instability is reached.

Abstract: A second member and a first member are applied with bias force to mechanically engage with each other at one of detent positions defining relative positions therebetween. An electric motor rotating a rotor therein when being supplied with electricity. Rotation of the rotor is transmitted to an output shaft manipulating the first member. A main controller controls the electric motor to switch the one of the plurality of detent positions. A rotor angle detecting unit detects rotor angle of the rotor. An output angle detecting unit detects output angle of the output shaft. The main controller includes a backlash calculating unit that calculates a backlash amount between the rotor and the first member in accordance with at least one of occurrence of a first region, in which change in the output angle is small with respect to change in the rotor angle, and a range of the rotor angle in the first region. The main controller incorporates the backlash amount into the control of the electric motor.

Abstract: An electric power steering control device includes a memory. The memory is accommodated in the electric power steering control device mounted on a vehicle, and permits rewrite and storage of data. Transmitting a signal from an external of the vehicle allows the data stored in the memory to be rewritten.

Abstract: In a stabilizer apparatus for a vehicle, an electronic control unit calculates a target current of an electric motor from vehicle speed, steering angle, and lateral acceleration, and increases and decreases actual current such that the calculated target current flows through the motor. The control unit decreases the actual current by a predetermined amount when the difference between the target current and the actual current becomes smaller than a predetermined value during control of increasing the actual current. The predetermined amount is equal to the difference between the determined target current at the time of the detection of the difference and current which is necessary to obtain, during control of decreasing the actual current, an output torque equal to the output torque of the speed reduction mechanism obtained as a result of the target current flowing through the electric motor.

Abstract: The atmosphere temperature calculator calculates an estimated atmosphere temperature value by subtracting a temperature rise amount of a temperature sensor which is calculated based on a motor drive detected current value from a detected temperature value of the temperature sensor. The overheating prevention calculator calculates estimated temperature values of a plurality of protection objects to be protected from overheating based on the estimated atmosphere temperature value and the motor drive detected current value and determines an upper limit of target current of driving a motor based on such estimated temperature values. The temperature compensation calculator calculates a temperature compensation current value to be added to a target current value in order to compensate a temperature characteristic of a predetermined portion based on the estimated atmosphere temperature value.

Abstract: A system and method for controlling an electric motor using real time predictions of motor capability based on thermal modeling and measurements is provided. The invention includes controllers for receiving and processing system input signals, strategies for: determining a maximum energy amount that can be put into the motor before the motor reaches a maximum allowable temperature; determining a motor power assist value that the motor can provide in a predetermined period of time before the motor reaches the maximum allowable temperature; determining a battery power assist value; determining a maximum power assist value that is the minimum of the motor power assist value and the battery power assist value; and comparing the maximum power assist value to a driver demand signal. Strategy outputs can be sent to a vehicle system controller and/or a power assist gauge.

Abstract: A method for automatically adjusting a vehicle stability enhancement (VSE) system is disclosed. The VSE system is used in conjunction with a steering system having a plurality of driver-selectable steering modes associated therewith. In an exemplary embodiment, the method includes configuring a reference model within the VSE system to generate desired vehicle handling aspects, the desired vehicle handling aspects being a function of one or more driver inputs to the steering system. Then, a determination is made as to which of the plurality of driver-selectable steering modes is activated, wherein each of the desired vehicle handling aspects generated is made further dependent upon a specific steering mode selected.

Abstract: A method is disclosed for determining a steering wheel angle calibration reference value in a vehicle. The vehicle includes a relative steering wheel angle sensor, which is unique in that it receives power directly from the vehicle's battery and interacts with the vehicle's car area network. The vehicle also includes an active yaw controller that interacts with the vehicle's car area network. The steering wheel angle calibration reference value only needs to be updated when power to the relative steering wheel angle sensor has been interrupted.

Abstract: A vehicle steering mechanism to compensate for instabilities including a vehicle frame, a front axle coupled to the vehicle frame, the front axle further coupled to two front wheels, a rear axle coupled to the vehicle frame, the rear axle further coupled to two rear wheels, an actuator for changing the direction and angle of the two rear wheels, a trailer hitch coupled to the frame, at least one sensor for measuring instability in the trailer hitch, a controller processing the measured instability, and where the controller controls the actuator and the direction and angle of the two rear wheels to compensate for the measured instability.

Abstract: An electronic power assisted steering system and method wherein vehicle operating parameters, such as steering rack rate and position, are employed to predict future current requirements of the power assisted steering system, and adjust vehicle operating parameters, such as engine and alternator systems, to assure the appropriate power supply to the power assisted steering system without voltage peaks or sags.

Abstract: A steerable drive axle for a motor vehicle including a rigid tubular housing, a pair of steering knuckles at opposite ends of the rigid tubular housing, an expanded chamber in the middle of the rigid tubular housing open on one side for access to a differential gear set in the expanded chamber, a differential cover for closing the open side of the expanded chamber, and an electrically-powered steering apparatus on the cover linked to the steering knuckles. The electrically-powered steering apparatus includes a rack bar passage in the differential cover, a rack bar supported in the rack bar passage for linear translation and linked to the steering knuckles, a pinion head rotatably supported on the differential cover having a pinion gear meshing with a rack gear on the rack bar, an electric motor mounted on the differential cover, and a speed reducer on the differential cover between the pinion head and an output shaft of the electric motor.

Abstract: A vehicle steering mechanism to compensate for instabilities including a vehicle frame, a front axle coupled to the vehicle frame, the front axle further coupled to two front wheels, a rear axle coupled to the vehicle frame, the rear axle further coupled to two rear wheels, an actuator for changing the direction and angle of the two rear wheels, a trailer hitch coupled to the frame, at least one sensor for measuring instability in the trailer hitch, a controller processing the measured instability, and where the controller controls the actuator and the direction and angle of the two rear wheels to compensate for the measured instability.

Abstract: The invention provides a method and computer usable medium, including a program, for steering a vehicle having driver-controlled front wheel steering and active rear wheel steering. A rear wheel steering angle static portion is determined based on a control gain and a front wheel steering angle. A slew-limited magnitude of desired lateral acceleration is determined based on a desired lateral acceleration. A multiplying factor is determined based on the slew-limited magnitude of desired lateral acceleration. A feed-forward rear steering angle is determined based on the multiplying factor, the rear wheel steering angle static portion, and a rear wheel steering angle dynamic portion.

Abstract: A steering system for an automotive vehicle having two front wheels and two rear wheels is provided.