4014 results about "Electric power steering" patented technology

The steering angle of a vehicle is monitored using position sensors of an electric motor of an electric power assisted steering (EPAS) system. A position of the electric motor corresponding to the straight-ahead, center position of the steering system is stored in non-volatile memory during a steering calibration procedure, such as an end-of-line calibration in a vehicle assembly plant. Following power loss due to a dead battery, a steering angle zeroing procedure performed in a vehicle stability control (VSC) system generates a center position with enough accuracy to be within one electrical cycle of the motor. The pre-stored electric motor position is then used to determine the electrical cycle where the center position was located, and accurate monitoring of steering angle is resumed.

A motor control apparatus includes a steering column having inserted therein a steering shaft to which steering torque is transmitted, a reduction gear box coupled to the steering shaft, and an electric motor that transmits a steering assisting force to the steering shaft via a reduction mechanism in the reduction gear box. The electric motor and its control unit including a control board mounted with a control circuit, are provided side by side in the reduction gear box. A connection terminal of the electric motor is electrically connected to the control unit directly. This minimizes a connection distance between the control unit and the electric motor.

A drive control device of an unconnected motor capable of resolving power shortage and increasing motor output without using a boost circuit, and an electric power steering device using the unconnected motor. The drive control device comprises an unconnected motor (12) having a rotor in which permanent magnets are allocated and a stator opposing the rotor, in which armature winding Lu to Lw of a plurality (N number) of phases are independently arranged, a pair of inverter circuits (34a, 34b) individually connected to both ends of each armature winding, and a drive control circuit (15) which drives the pair of inverter circuits (34a, 34b) with a predetermined number (e.g. 2N) of PWM drive control signals.

An electric power steering apparatus can improve heat dissipation of a power board. A heat sink is mounted on the power board in surface contact therewith, on which power board there is mounted a bridge circuit including a plurality of semiconductor switching elements for switching an electric current supplied to an electric motor in accordance with torque assisting a steering wheel. The heat sink has a plurality of protrusions formed on a surface thereof at a side opposite to the power board.

A system and method for determining whether a vehicle driver is holding a steering wheel of the vehicle while the vehicle is in an autonomous driving mode. The vehicle will include an electric power steering (EPS) system and may include an active front steering (AFS) system, both of which include a motor that can apply a high frequency and low amplitude perturbation signal to the steering wheel of the vehicle that is not felt by the vehicle driver and does not cause the vehicle to turn, but is able to be detected by a steering angle sensor. The method subtracts a steering angle command signal from the steering angle signal and removes road disturbances, and then determines whether the induced perturbation signal is present in the steering angle sensor signal. If the perturbation signal is present, then the system knows that the vehicle driver is not holding the steering wheel.

When a shaft misalignment detection part detects occurrence of a shaft misalignment that is a misalignment in a relative position in a radial direction of a rotary shaft between a magnet part and a sensor part, the shaft misalignment detection part outputs a shaft misalignment determination flag to a correction part and a control change instruction part. The correction part calculates a motor rotational angle so as to reduce a detection error caused by the shaft misalignment. The control change instruction part outputs instructions of changing calculation methods so that influence by the detection error decreases to an assist torque setting part and an assist current instruction part.

A small-sized motor for electric power steering, in which coil connection can be easily performed with space saving, and a method for manufacturing the motor. Multi-phase stator coils assembled in a stator coil are connected per phase by connecting rings at coil ends of the stator coils. A bus bar supplied with electric power from the exterior is stacked onto the connecting rings in the axial direction of the motor and is electrically connected to the connecting rings.

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

When it is determined that a malfunction has occurred in a rotational angle sensor, an electronic control unit changes the control manner from the normal assist control to the sensorless assist control. In the sensorless assist control, an assist stop command unit receives the information concerning the motor rotational angular speed ωm from an angular speed conversion unit. Then, the motor rotational angular speed ωm is compared with the threshold value ωm1. If the motor rotational angular speed ωm is equal to or higher than the threshold value ωm1, an assist enabling signal is transmitted to a PWM voltage production unit to continue the power assist. On the other hand, if the motor rotational angular speed ωm is lower than the threshold value ωm1, a stop command signal is transmitted to the PWM voltage production unit to stop the power assist.

The invention proposes a lane keeping assist system and a lane keeping assist method. The method comprises the steps of comprehensively detecting a people-vehicle-road driving environment through a lane environment detection module, a vehicle state detection module, a driver driving state detection module and a vehicle and road surface rolling friction coefficient detection module; calculating a corresponding detection signal through a lane keeping control module; judging whether a vehicle deviates from a lane or not; performing transverse lane return-to-center control through cooperative control of an electric power steering system (EPS) and an electronic stability program (ESP), and keeping a longitudinal safety distance through ESP control; and giving an alarm for reminding. Through the technical scheme provided by the invention, the driving safety of vehicle driving is remarkably improved; and the lane keeping is realized through the cooperative control of the EPS and the ESP, so that on the premise of ensuring the driving safety of the vehicle, the working comfort of the lane keeping assist system can be improved to the maximum extent.

A control apparatus for a multi-phase rotary machine includes a control unit and a plurality of power supply systems including respective inverter units. When a short-circuiting failure occurs in one of the systems due to an ON-failure in any one of FETs in an inverter unit of the failure system, the control unit stops driving of the rotary machine by bringing all the FETs in the failure system into the OFF state. The control unit controls FETs of the non-failure system such that a brake torque generated in the failure system is cancelled or the influence of the brake torque exerted on the driving of the motor is reduced.

In an operation range of an actuator subjected to quick acceleration and deceleration, a motor drive apparatus, an electric actuator and an electric power steering apparatus capable of continuous torque control up to the high drive speed and high torque area. A controller comprises a voltage saturation detecting means for detecting the voltage saturation of the output voltage of an inverter circuit, based on the battery voltage, and a waveform controller that converts the drive waveform of the inverter circuit into the waveform created by superimposing harmonics of high odd-numbered order on a sinusoidal wave as a fundamental wave of the modulated wave modulated by a PWN carrier wave; and continuously changes the ratio of superimposing the high-order harmonics in response to the voltage saturation detected by a voltage saturation detecting means. This arrangement allows the controller to continuously change the drive waveform of the inverter circuit.

An electric power steering system is provided which is capable of providing a favorable steering feeling without using compensation logics such as of inertia compensation and friction compensation. The electric power steering system includes road-noise suppression control means (213) for controlling a steering assist motor (9) in a manner to damp torque transmission in a higher frequency region representing road noises than a frequency region representing road information. A friction value of a steering mechanism (A) is decreased enough to allow the intrinsic vibrations of the steering mechanism (A) to appear. Rotor inertia of the steering assist motor (9) is set to a value small enough to allow the frequencies of the intrinsic vibrations to be present in the frequency region where the torque transmission is damped by the road-noise suppression control means (213).

The disclosure concerns a a motor drive apparatus, an electric actuator and an electric power steering apparatus capable of continuous torque control up to the high drive speed and high torque area, in order to enable quick acceleration and deceleration. A controller comprises a voltage saturation detecting apparatus for detecting the voltage saturation of the output voltage of an inverter circuit, based on the battery voltage, and a waveform controller that converts the drive waveform of the inverter circuit into the waveform created by superimposing harmonics of high odd-numbered order on a sinusoidal wave as a fundamental wave of the modulated wave modulated by a PWN carrier wave; and continuously changes the ratio of superimposing the high-order harmonics in response to the voltage saturation detected by a voltage saturation detecting means. This arrangement allows the controller to continuously change the drive waveform of the inverter circuit.

An electric power steering apparatus requires no external connecting member connecting between a power main body and a control main body, and hence can be reduced in size and cost, and the reliability of electrical connection between the power main body and the control main body can be improved. High current parts constituting the power main body and low current parts constituting the control main body are mounted on opposite sides of a circuit board, and are electrically connected with one another via conductor layers of the circuit board and through holes formed therein.

The present invention provides a control apparatus for an electric power steering apparatus comprises: a steering assist command value calculating section; a current control section that calculates a voltage command value; and a motor driving section that drives a motor based on the voltage command value, wherein an assist power from the motor is applied to a steering system, the control apparatus is characterized in that an SAT measuring section, that inputs an angular speed and an angular acceleration of the motor, the steering assist command value and the torque signal therein so as to estimate an SAT, is provided, and the SAT obtained by the SAT measuring section is feedbacked to the steering assist command value via a feedback section composed of a phase compensating section and a gain section.

Method, system and non-transitory computer-readable medium for fail-safe performance of a lane centering system. An electrical power steering (EPS) system of a vehicle is monitored for a failure and operation of the lane centering system is switched to a differential braking controller to output differential braking commands to a differential breaking system upon determining that a failure of the EPS system has occurred, where the output braking commands direct the differential braking system to apply force a brake for a wheel of vehicle, such by the applied braking force the vehicle follows a desired path determined for a lane centering operation.

An angle sensor for sensing the absolute angular position of a rotatable body, such as a rotating shaft of an electric power steering system for an automobile, is disclosed.

An electric power steering system for an automotive vehicle, includes a torque sensor disposed to a steering shaft to detect a steering torque. A first pinion is disposed to the steering shaft. A rack shaft is in mesh with the first pinion and connected with the steering shaft to change a rotational motion of the steering shaft to an axial motion of the rack shaft and provided to be operated in relation to the steering shaft. A first motor is connected with the first pinion to generate a steering assist torque in accordance with the steering torque detected by the torque sensor. A second pinion is disposed to be separate from the first pinion and in mesh with the rack shaft. A second motor is connected with the second pinion to generate a steering assist torque in accordance with the steering torque.

The stator core of a motor comprises an annular back core, and a plurality of tees created separately from the back core and secured onto the inner periphery of the back core. A stator coil is wound on each of the tees by a distributed or concentrated winding method. The stator core and stator coil are formed by molding.

Reduction in costs and size of an electric driving device is achieved and reliability of electrical connection thereof is enhanced. The device comprises: an electric motor; a controller that is disposed coaxially with the axis of the electric motor rotation shaft and takes control of driving the electric motor; a motor terminal whose end extends from the electric motor toward the controller; and an output terminal whose end extends from the controller toward the electric motor; wherein a portion of the motor terminal including the end thereof and that of the output terminal including the end thereof each are formed to extend in parallel to an axial direction of the electric motor, and overlappingly connected with each other.

The invention discloses a full-automatic parking system. The parking system comprises a full-automatic parking controller, as well as an environment information collecting system, an electric power-assisted steering system, an engine managing system, a transmission controller, an electronic stable system for a car body and an electronic parking system that are in communication connection with the full-automatic parking controller; the full-automatic parking controller utilizes parking information acquired by the environment information collecting system to formulate feasible parking routes, works out relevant instructions, sends the instructions to actuating mechanisms, acquires actual feedback signals for real-time revision of the parking routes, and realizes the closed-loop control on a car. The parking system completely adopts the conventional mechanisms of the car as actuators to reliably and accurately realize full-automatic parking.

A control device for an electric power steering apparatus includes a control unit which controls a motor giving steering assist force to a steering system according to a current command value computed based on steering toque and vehicle speed in a vector control manner and an advance angle map for compensating for a phase lag occurring in a motor current relative to the current command value. Advance angle compensation is made for the current command value based on the advance angle map.

The present invention is to provide a control system for a hybrid vehicle in which, even if during traveling of the hybrid vehicle, a battery defect arises in a high-voltage power source, battery-less emergency traveling can be achieved over a sufficiently long distance, and the steering assist force can be effectively prevented from changing rapidly during traveling. The control section includes high-voltage power source defect processing unit. During execution of a mode in which the high-voltage power source, is reduced so that the reduced voltage is supplied to an electric power steering device (EPS), when a defect occurs in the high-voltage power source, the high-voltage power source defect processing unit shifts to a mode in which the low voltage of a low-voltage power source is increased so that the increased voltage is supplied to the EPS. The high-voltage power source defect processing unit then disconnects the high-voltage power source and the driving circuit from each other. Thereafter, the control section shifts to a mode in which a voltage corresponding to power generated by a generator is reduced so that the reduced voltage is supplied to the EPS, while allowing the generator to drive a traveling motor.

The invention relates to a tensioning device for use in vehicle power steering assembly, in particular, having a drive unit for rotating an input pulley rotatably connected to an output pulley via a flexible belt. The tensioning device includes a housing and an arm movably attached relative to the housing. A contact device is mounted on the arm and is adapted to be engaged with a portion of the belt between the input and output pulleys. The arm is movable relative to the belt to position the contact device against the belt to provide tension on the belt.

In a multi-system motor drive apparatus, a power supply relay is interrupted when a first power supply system fails at time t0. A power control unit doubles a current supplied to an inverter of a second power supply system thereby to supplement the electric power, which has been supplied by an inverter of the first power supply system. The total output of inverters is thus maintained before and after the failure. After an elapse of a predetermined period, the electric power supplied by the second power supply system is reduced gradually so that the inverter of the second power supply system will not be operated to supply the doubled power for a long period.

A method and system for stabilizing a vehicle employing an electric power steering system is disclosed. The method includes receiving as inputs, a desired torque command representative of a steering wheel torque and a vehicle speed signal. The method also includes acquiring an acceleration signal representative of vehicle acceleration. The method further comprises generating an assist torque command, which is a combination of the desired torque command and a compensating torque command where the compensating torque command is responsive to the vehicle speed signal and the acceleration signal.

Disclosed herein is a method for controlling an electric power steering system, wherein a motor is controlled by vector control and driven by a current command value calculated on the basis of a parameter such as a steering torque to provide a steering assist power to a vehicle steering system, and further wherein the current command value is limited on the basis of desired output characteristics and a desired angular speed during a field-weakening control and a non-field-weakening control of the vector control.