Abstract: An electric power steering apparatus includes a temperature sensor measuring a temperature at a starting of a vehicle, a motor position sensor detecting a relative steering angle of a motor, a cumulative transfer calculation unit calculating a cumulative transfer quantity of a rack bar by information detected in the motor position sensor, a counter calculating an elapsed time from a starting time of the vehicle, a friction coefficient determination unit determining a friction coefficient according to information inputted from the temperature sensor, the cumulative transfer quantity calculation unit, and the counter, respectively, by using a setting map of a friction coefficient, and a target current calculation unit calculating a compensation quantity for a friction by using the friction coefficient determined in the friction coefficient determination unit and determining a target current.

Abstract: A speed control method of a vehicle including the steps of obtaining a steering angle, a velocity error and a distance error. The velocity and the distance error being determined by mathematical combinations of a GPS position, a required path and speed set points. The steering angle, velocity errors and distance error are applied to fuzzy logic membership functions to produce an output that is applied to a velocity rule base. An output from the velocity rule base is defuzzified to produce a speed signal.

Abstract: A parallel parking assistant system integrated with a vehicle and method thereof are provided, the parking assistant system including a first sensor configured to determine a first distance, a second sensor configured to determine a second distance, and a controller configured to provide commands as a function of the first and second determined distances. The commands include a first command configured to command a steering system to be in a clockwise position while the vehicle is moving in a reverse direction for a first reversing distance, a second command configured to command the steering system to be in a substantially straight position while the vehicle is moving in a reverse direction for a second reversing distance, and a third command configured to command the steering system to be in a counter-clockwise position while the vehicle is a moving in a reverse direction for a third reversing distance.

Abstract: A control system for controlling a steering system to maintain stability of the steering system is provided. The control system includes an operating conditions module that estimates at least one operating gain based on an operating condition of the steering system. A blend module estimates a blend value based on the at least one operating gain. A steering assist module generates a steering assist command based on the blend value.

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: A parallel parking assistant system integrated with a vehicle and method thereof are provided, the parking assistant system including a first sensor configured to determine a first distance, a second sensor configured to determine a second distance, and a controller configured to provide commands as a function of the first and second determined distances. The commands include a first command configured to command a steering system to be in a clockwise position while the vehicle is moving in a reverse direction for a first reversing distance, a second command configured to command the steering system to be in a substantially straight position while the vehicle is moving in a reverse direction for a second reversing distance, and a third command configured to command the steering system to be in a counter-clockwise position while the vehicle is a moving in a reverse direction for a third reversing distance.

Abstract: It is an object of the present invention to provide a controller for a steering apparatus having easy operation of an adjustment of a tilting angle. The steering apparatus comprises a tilting mechanism adjusting a tilting angle of a steering wheel, and an electrical motor driving the tilting mechanism. The controller for the steering apparatus 1 detects the tilting angle based on a rotational angle of the screw shaft. The controller defines the predetermined supplying current according to the detected amount of the tilting angle as the supplying current to the electrical motor.

Abstract: An electric power steering control apparatus can reduce steering torque even in a steering holding state or a slight steering state without providing an unpleasant feeling to a driver. The apparatus includes a torque sensor for detecting steering torque generated by the driver for a vehicle, a motor for generating assist torque to assist the steering torque, a rotational speed detector for detecting the rotational speed of the motor, a torque controller for calculating an assist torque current corresponding to the assist torque based on the steering torque, and a damping control section for calculating a damping current to be added to the assist torque current to suppress vibrations generated in a steering system of the vehicle. The damping controller reduces a damping control gain to calculate the damping current when the rotational speed of the motor is equal to or less than a predetermined speed.

Abstract: A raster-based system for GNSS guidance includes a vehicle-mounted GNSS antenna and receiver. A processor provides guidance and/or autosteering commands based on GNSS-defined pixels forming a grid representing an area to be treated, such as a field. Specific guidance and chemical application methods are provided based on the pixel-defined treatment areas and preprogrammed chemical application prescription maps, which can include variable chemical application rates and dynamic control of the individual nozzles of a sprayer.

Abstract: A method and system for assisting the steering of steered wheels of a vehicle, in which a phase lead is applied between a steering wheel and a steering rack element to reduce response time of the vehicle to an action performed by the driver on the steering wheel.

Abstract: A traction control device includes: rotation speed detectors provided to wheels; a control-start determiner that determines whether or not to control a braking mechanism and a differential adjusting mechanism based on rotation speeds; a braking mechanism controller that controls the braking mechanism based on a result of the determination of the control-start determiner; and a differential adjusting mechanism controller that controls the differential adjusting mechanism based on the result of the determination of the control-start determiner, in which the control-start determiner includes: a right-left-wheel rotation speed difference calculating section; a front-rear-wheel rotation speed difference calculating section; and a control-start determining section that determines whether or not to start controlling at least one of the braking mechanism and the differential adjusting mechanism when one of rotation speed differences reaches or exceeds a predetermined threshold.

Abstract: A steering control method including the steps of obtaining a heading error, obtaining a velocity value, obtaining a distance error, applying the heading error and defuzzifying an output from a steering rule base. The velocity value and the distance error are applied along with the heading error to fuzzy logic membership functions to produce an output that is applied to a steering rule base. An output from the steering rule base is defuzzified to produce a steering signal.

Abstract: A positioning system (1) provided with an actuator (2) having a wave gear device (4) is driven and controlled by a semi-closed loop control for controlling the load position of a load device (5) based on the motor position of a motor shaft (31) of a motor (3). In a method for compensating for an angular transmission error by compensating for a motor shaft synchronous component ?Sync that occurs in synchrony with the motor position and is a relative rotation-synchronous component that includes an angular transmission error component of the wave gear device (4), the positioning system (1) is represented as a two-inertia model, and the motor shaft synchronous component ?Sync is represented as an oscillation source for producing a twisting action between the two inertia bodies in the two-inertia model.

Abstract: A method for driver support in a vehicle in which a driver assistance system monitors a driving situation of the vehicle. Support takes place after a confirmation or after the absence of an abort instruction, a dialogue about the extent of support the driver wishes being conducted between the driver and the driver assistance system.

Abstract: Embodiments of the invention provide a computer program product embodied on a computer readable storage medium. The computer program product is encoded with instructions configured to control a controller to perform a process. The process includes setting a target steering angle for the vehicle based on a steering amount of the vehicle, setting a target torque difference between right and left steered wheels based on the target steering angle, and setting a target driving/braking force for the vehicle based on an acceleration amount and a braking amount of the vehicle. The process also includes setting each target torque for the right and left steered wheels based on the target torque difference and the target driving/braking force and controlling driving of the steered-wheel motors based on the target torque. The kingpin point is positioned closer to the vehicle on an inside portion of an inside sidewall of a steered wheel.

Abstract: A plurality of electric control units are connected to perform data-communication through a communication line. Each electric control unit comprises a recording means for recording data and a communication means, to control an operation of an object to be controlled. One of the plurality of electric control units determines whether it is possible to record data in the recording means, and records the data in the recording means when it determines that it is possible to record the data in the recording means. The “one of the plurality of electric control units” transmits the data to other electric control unit when it determines that it is not possible to record the data in the recording means. The “other electric control unit” receives the transmitted data and records it in own recording means.

Abstract: The present invention provides a steering control apparatus that controls steering of a vehicle of a steer-by-wire type, and includes steered-wheel motors that apply separate torques to right and left steered wheels respectively, a rod member that couples the right and left steered wheels so that the steered wheels can be steered, and a steering controller that controls driving of the steered-wheel motors. In each steered wheel, a center of the contact face thereof and a kingpin point thereof are offset in a lateral direction of the vehicle, and the steering controller controls driving of the steered-wheel motors so as to generate a torque difference between the right and left steered wheels, and provides a steering effort in accordance with this torque difference for each of the right and left steered wheels via the rod member, thereby to steer the vehicle.

Abstract: A steering control method including the steps of obtaining a heading error, obtaining a velocity value, obtaining a distance error, applying the heading error and defuzzifying an output from a steering rule base. The velocity value and the distance error are applied along with the heading error to fuzzy logic membership functions to produce an output that is applied to a steering rule base. An output from the steering rule base is defuzzified to produce a steering signal.

Abstract: A steering control method including the steps of obtaining a heading error, obtaining a velocity value, obtaining a distance error, applying the heading error and defuzzifying an output from a steering rule base. The velocity value and the distance error are applied along with the heading error to fuzzy logic membership functions to produce an output that is applied to a steering rule base. An output from the steering rule base is defuzzified to produce a steering signal.

Abstract: The method for generating an integrated guidance law for aerodynamic missiles uses a strength Pareto evolutionary algorithm (SPEA)-based approach for generating an integrated fuzzy guidance law, which includes three separate fuzzy controllers. Each of these fuzzy controllers is activated in a unique region of missile interception. The distribution of membership functions and the associated rules are obtained by solving a nonlinear constrained multi-objective optimization problem in which final time, energy consumption, and miss distance are treated as competing objectives. A Tabu search is utilized to build a library of initial feasible solutions for the multi-objective optimization algorithm. Additionally, a hierarchical clustering technique is utilized to provide the decision maker with a representative and manageable Pareto-optimal set without destroying the characteristics of the trade-off front. A fuzzy-based system is employed to extract the best compromise solution over the trade-off curve.

Abstract: The present invention is typically embodied to exert active control of two same-shipboard cranes performing joint lifting of a payload. Sensory signals indicative of ship motion, and of luff angle and hoist line length of both cranes, are transmitted to a computer. The sensory signals are processed by the computer using a ship motion cancellation algorithm, which solves for values of the respective luff angles and hoist line lengths of both cranes, such values achieving static equilibrium (e.g., zero motion horizontally, vertically, and rotationally in the same vertical geometric plane) of the suspended payload. Inverse kinematic control signals in accordance with the mathematical (e.g., minimum norm) solutions are transmitted by the computer to respective luff angle actuators and hoist line length actuators of both cranes so that the suspended payload tends toward steadiness. Inventive control thus acts on a continual basis to significantly reduce pendulation during the two-crane lifting operation.

Abstract: The control optimization method for helicopters carrying suspended loads during hover flight utilizes a controller based on time-delayed feedback of the load swing angles. The controller outputs include additional displacements, which are added to the helicopter trajectory in the longitudinal and lateral directions. This simple implementation requires only a small modification to the software of the helicopter position controller. Moreover, the implementation of this controller does not need rates of the swing angles. The parameters of the controllers are optimized using the method of particle swarms by minimizing an index that is a function of the history of the load swing. Simulation results show the effectiveness of the controller in suppressing the swing of the slung load while stabilizing the helicopter.

Abstract: A system and method for providing steering control for lane changing and lane centering purposes in an autonomous or semi-autonomous vehicle system. A vehicle vision system calculates roadway lane marking information, such as lateral offset, yaw angle and roadway curvature with respect to the vehicle's centered coordinate system. The roadway is then modeled as a second order polynomial equation. The method then predicts roadway lateral position and yaw angle over a pre-defined lane change completion time using a vehicle dynamic model. The method then compares a predicted vehicle path with a desired vehicle path to generate an error value, and calculates a steering angle command to minimize the error value, where the steering angle command is calculated as a function of vehicle lateral position, vehicle lateral speed, vehicle yaw rate and vehicle yaw angle. The steering angle command is then sent to the vehicle steering system.

Abstract: The fuzzy logic-based control method for helicopters carrying suspended loads utilizes a controller based on fuzzy logic membership distributions of sets of load swing angles. The anti-swing controller is fuzzy-based and has controller outputs that include additional displacements added to the helicopter trajectory in the longitudinal and lateral directions. This simple implementation requires only a small modification to the software of the helicopter position controller. The membership functions govern control parameters that are optimized using a particle swarm algorithm. The rules of the anti-swing controller are derived to mimic the performance of a time-delayed feedback controller. A tracking controller stabilizes the helicopter and tracks the trajectory generated by the anti-swing controller.

Abstract: There is provided a control apparatus that controls a motor of an electric power steering system to assist a steering effort of an operator. The control apparatus includes a sensor, a parameter computer, a difference computer, a target torque computer, and a motor driver. The parameter computer computes a current value of one of physical parameters of one of constituents of the electric power steering system based on a steering parameter determined by the sensor referring to an equation of motion. The difference computer computes a difference between the current value of the one of the physical parameters computed by the parameter computer and a predetermined value of the one of the physical parameters. The target torque computer computes a target torque of the motor which compensates for the difference between the current value and the predetermined value of the one of the physical parameters.

Abstract: A system for decoupling steering rack force disturbances in electric steering may comprise a steering wheel angle sensor, a yaw rate sensor, a lateral acceleration sensor, and a steering torque sensor. The system may also comprise a tire force generator configured to receive signals from the steering wheel angle sensor, the yaw rate sensor, and the lateral acceleration sensor and send a reference rack force to a controller. The system may further comprise a rack force observer configured to receive signals from the steering torque sensor and send an estimated rack force to the controller, wherein the controller is configured to receive signals from the tire force generator and the rack force observer, compare the estimated rack force with the reference rack force to determine a rack force disturbance, and adjust an auxiliary torque based on the rack force disturbance.

Abstract: A method for controlling a steering system, the method including, receiving a first signal including a position of a component in the steering system, receiving a second signal including a disturbance signal operative to indicate an effect of a first torque disturbance in the steering system, calculating a first counter acting torque command signal operative to minimize the first torque disturbance as a function of the position of the component and the disturbance signal, and sending the first counter acting torque command signal to a motor.

Abstract: A riskiness reference value Riskm is corrected and calculated for each target object according the a road surface friction coefficient based on a vehicle-to-target time and a collision allowance time, and a riskiness Riskm (?Am) for each three-dimensional object is set based on the riskiness reference value Riskm with a range which uses a probability distribution given in an azimuthal angle direction where each target object exists, whereby a riskiness Risk (?A) is set for each azimuthal angle. Then, alarming and brake controlling are made to be executed according to a riskiness Risk (0) at an azimuthal angle of 0, and a steering angle control amount ?strt is obtained from the current riskiness Risk (?A) of each azimuthal angle and an estimated riskiness Risk (?A)e of each azimuthal angle after a set time period.

Abstract: A main controller calculates permissible driving forces of individual wheels from a road-surface friction coefficient, ground loads of the individual wheels, and lateral forces of the individual wheels. The main controller then calculates a permissible engine torque on the basis of the calculated permissible driving forces so as to limit engine output. In addition, based on the calculated permissible driving forces, the main controller calculates a transfer-clutch torque for front-rear driving-force distribution control, a rear-wheel torque shift amount for left-right driving-force distribution control, and a steering-angle correction amount for steering-angle control.

Abstract: An inventory storage and retrieval system and method are provided for a shipping or storage facility. In an embodiment, the system includes: (a) a mobile computer and radio on a load-handing vehicle; (b) sensors on the vehicle to determine the ground location and orientation of the vehicle; (c) encoders that determine the position of a lifting mechanism relative to a chassis of the vehicle; and (d) a base computer and radio that communicates with the vehicle. The system maintains an inventory database of items and their respective storage locations in three dimensions as a result of the loading activity of the vehicle. The data can be used to guide the vehicle for ground movement generally to a storage location, appropriately orient the vehicle, and then to move the lifting mechanism of the vehicle to deposit or retrieve the item at a particular storage location.

Abstract: A vehicle steering control system includes a variable transmission ratio device that rotates an output shaft relative to an input shaft so as to change the transmission ratio, and a locking device that is switched between a lock-on state in which the transmission ratio between the input shaft and the output shaft is inhibited from being changed and a lock-off state in which the transmission ratio between the input shaft and the output shaft is allowed to be changed. The variable transmission ratio device includes an electric motor and a speed reduction mechanism. The locking device inhibits the input shaft and a rotor of the electric motor from rotating relative to each other when placed in the lock-on state, and allows the input shaft and the rotor to rotate relative to each other when placed in the lock-off state.

Abstract: A steering system includes a sport mode select/release switch, a steering control portion which changes steering mode stored in a steering mode map in response to signal from the sport mode select/release switch and an electro mechanical steering device controlled by the steering mode of the steering control portion.

Abstract: An angle sensing system for sensing a rotating angle of a steering wheel includes a sensing unit, a processing unit, and a storage unit. The sensing unit detects the rotating angle of a steering column connected to the steering wheel and outputting a sensing signal based on the rotating angle. When the steering column rotates for a circle, the sensing signal presents a non-continuous status. The processing unit calculates the relative angle in a single loop of the steering column based on the sensing signal and the number of loops according to the number of the non-continuous status. The storage unit stores the information of the relative angle and the number of loops. Based on the number of loops and the relative angle, the rotating angle of the steering wheel is detected.

Abstract: The invention relates to a method for compensating for drive influences of a drive train of a motor vehicle on its steering system, said motor vehicle having an electric power steering system. A drive train simulation model which is integrated into the motor vehicle and permanently activated is used to determine disturbance variables from a driven behavior so that a compensation torque which counteracts the disturbance variables is generated for the power steering system.

Abstract: A learning controller overcomes tuning problems in vehicle simulation programs by estimating requisite vehicle-specific parameters, effectively learning from its mistakes, as the vehicle is automatically driven around a track. After a sufficient period of calibration, the learned parameters are automatically saved to a car-specific file. The file parameters may be loaded in the controller in the future to optimally control a vehicle without the need to re-run the learning procedure.

Abstract: Provided is a power steering apparatus capable of suppressing an abrupt change in steering force and preventing a deterioration in steering feeling even in the event of a transition from power steering to manual steering. The power steering apparatus includes a torque sensor, a motor of a permanent magnet field type, and a controller having a motor driving unit and an abnormality monitoring unit, for controlling the driving of the motor. The motor driving unit includes an inverter for driving the motor, and a drive signal generating unit for calculating a target current caused to flow through the motor and outputting a drive signal of the inverter based on the target current. The abnormality monitoring unit includes an abnormality processing unit for constituting a closed-loop circuit including the motor in stopping the driving of the motor.

Abstract: A traction control system (30) for a machine (10) includes a driven wheel (22) operated by a motor that is controlled by an electronic controller (54). A speed sensor (44) measures the speed of the driven wheel (22), and communicates a wheel (22) speed to the electronic controller (54). A travel speed sensor (44) measures the travel speed of the machine (10) and communicates it to the electronic controller (54). A steering sensor (44) measures a displacement of the machine (10)'s steering system (28), and communicates a steering angle to the electronic controller (54). The electronic controller (54) calculates a speed ratio, based on the wheel (22) speed and the travel speed, and an expected slip ratio, based on the steering angle. The speed ratio is corrected by application of the expected slip ratio to yield a corrected speed ratio that is indicative of a slip condition. The operation of the motor is then adjusted to address the slip condition.

Abstract: A human perception model for a speed control method obtains a steering angle, a velocity error and a distance error. The steering angle and a measure of operator aggressiveness are applied to the model. The output is defuzzified. The steering angle, the velocity error and the distance error are applied to fuzzy logic membership functions to produce an output that is applied to a velocity rule base. The measure of operator aggressiveness is input to the velocity rule base. The output from the velocity rule base is defuzzified to produce a speed signal.

Abstract: A vehicular steering control apparatus is comprised of a steering system of receiving a steering torque inputted by a driver, a torque control actuator connected to the steering system to produce an actuator torque relative to the steering torque and a steering controlling section connected to the torque actuator. The steering controlling section controls the torque control actuator and increases a phase delay of the actuator torque relative to the steering torque toward a neighborhood of 180° as the frequency of the inputted steering torque increases.

Abstract: In a steering system having a variable gear transmission system and an electrical power steering system, respective compensation amounts for first and second electric motors are produced by a first mathematical model. The compensation amounts are added to command values (v1, v2) to generate final command signals (igref, ipref) to the respective electric motors. According to the above structure and operation, a mutual interference between two control systems can be suppressed.

Abstract: A collision prediction ECU of a collision prediction apparatus estimates a state of presence of a detected front obstacle. At this time, the collision prediction ECU estimates the state of presence on the basis of road shape data supplied from a navigation ECU of a navigation apparatus. Further, the collision prediction ECU checks and corrects the calculated road gradient value. At this time, the collision prediction ECU corrects the gradient value on the basis of road gradient data supplied from the navigation ECU. Further, the collision prediction ECU changes a collision avoidance time on the basis of travel environment data supplied from the navigation ECU. Moreover, the collision prediction ECU obtains an ETC gate pass-through signal from the navigation ECU and determines whether the vehicle is passing through the gate. The collision prediction apparatus performs collation prediction on the basis of the corrected values.

Abstract: A parking assist device includes a monitor (10) for displaying a captured image from a camera (12), assist information output means for providing assistance during introduction of a vehicle into a parking position, and correction control means (31) for correcting an inappropriate operation performed when the vehicle is introduced into the parking position. When a steering operation, an accelerator operation, or a brake operation is inappropriate, the correction control means (31) performs control to correct the travel course and the stop position. Thus, even if the driver performs an inappropriate operation when introducing the vehicle into the parking position, the driver can appropriately introduce the vehicle into the parking position according to the display on the monitor (10).

Abstract: A system for decoupling steering rack force disturbances in electric steering may comprise a steering wheel angle sensor, a yaw rate sensor, a lateral acceleration sensor, and a steering torque sensor. The system may also comprise a tire force generator configured to receive signals from the steering wheel angle sensor, the yaw rate sensor, and the lateral acceleration sensor and send a reference rack force to a controller. The system may further comprise a rack force observer configured to receive signals from the steering torque sensor and send an estimated rack force to the controller, wherein the controller is configured to receive signals from the tire force generator and the rack force observer, compare the estimated rack force with the reference rack force to determine a rack force disturbance, and adjust an auxiliary torque based on the rack force disturbance.

Abstract: A method for controlling the driving dynamics of a vehicle provides that a steering movement is carried out on the basis of a set value, which is calculated as a function of a deviation between a desired value and an acquired actual value of a vehicle state variable. In this method, at least one membership degree of an acquired value of a steering angle, which is set by a driver, and/or of a steering angle gradient, which is set by the driver, in a predetermined fuzzy set, are/is determined, and a value of the set value is changed as a function of the membership degree.

Abstract: The present invention concerns a system of automatic control of manoeuvre of motor crafts that allows, in a reliable and efficient way, to simplify piloting of multi-motor crafts, particularly in manoeuvres within restricted spaces such as for instance, but not exclusively, during phases of mooring, anchoring, or refuelling. In particular, the system automatically compensates the effects of currents, wind and other possible external disturbances upon the craft motion, performing the required movement or maintaining the position and the bow orientation set by the pilot. The present invention further concerns the related method of automatic control of manoeuvre, the processes of calibrating the system, the apparatuses and instruments apt to perform the method, and the motor crafts provided with such a system.

Abstract: A system that classifies driver driving skill based on on-ramp or off-ramp maneuvers. The system reads sensor signals for vehicle speed and vehicle yaw rate. The system determines that the vehicle has made an on-ramp or off-ramp maneuver using the vehicle speed signal and the yaw-rate signal and then classifies the driver's driving skill using selected discriminant features obtained or derived from the on-ramp or off-ramp maneuver.

Abstract: A vehicle steering control method including the steps of obtaining a heading error, obtaining a velocity value, obtaining a distance error, applying the heading error, inputting a measure of operator aggressiveness and defuzzifying an output from a steering rule base. The velocity value and the distance error are applied along with the heading error to fuzzy logic membership functions to produce an output that is applied to a steering rule base. A measure of the operator aggressiveness is input to the steering rule base. An output from the steering rule base is defuzzified to produce a steering signal.

Abstract: In deceleration control apparatus and method for an automotive vehicle, a deceleration control is performed on the basis of a turning of the vehicle; and a controlled variable of the deceleration control is decreased when the vehicle is traveling on an outlet of a curved road.

Abstract: A parallel parking assist system and a method for evaluating an area for use as a parking space for a host vehicle, the parallel park assist system comprises a ultra wideband radar sensor disposed in the host vehicle, wherein the radar sensor obtains a measurement data relating to a potential parking space and transmits a data signal representing the measurement data, a processor adapted to receive the transmitted data signal from the sensor, analyze the data signal, and transmit an alert signal in response to the analysis of the data signal, and a user interface adapted to receive the alert signal and provide an alert to the driver of the host vehicle in response to the alert signal, wherein the alert signal represents the suitability of the potential parking space.

Abstract: An electric power steering system includes: a band-stop filter 15a having a transfer function G1(s) for suppressing resonance, and a phase compensator 15b having a transfer function G2(s). The above function G1(s) is represented by an expression G1(s)=(s2+2?11?1+?12)/(s2+2?12?1+?12), where s is a Laplace operator, ?11 is a damping coefficient, ?12 is a damping coefficient, and ?1 is an angular frequency. On the other hand, the above function G2(s) is represented by an expression G2(s)=(s2+2?21?2+?22)/(s2+2?22?2+?22),where s is a Laplace operator, ?21 is a damping coefficient, ?22 is a damping coefficient, and ?1 is an angular frequency. Furthermore, the above damping coefficients ?21, ?22 satisfy an expression ?2124 ?22?1.Thus, a filter such as a phase compensator may attain a design freedom while preventing the increase of arithmetic load, whereby both the suppression of resonance and a good assist response in a normal steering speed region, for example, may be achieved.