A fail safe apparatus for an MDPS system may include: a vehicle speed sensor configured to measure a vehicle speed; a gear stage input unit configured to receive a gear stage from a transmission of the vehicle; a GPS vehicle speed calculation unit configured to calculate a GPS vehicle speed based on location information of the vehicle; and a control unit configured to determine whether the vehicle speed is an error, based on one or more of the vehicle speed, the gear stage, and the GPS vehicle speed, and determine vehicle speed data of the MDPS system based on one or more of the gear stage and the GPS vehicle speed.

In a motor control device that can perform more appropriate motor control, a switching arm has a first upper FET, a second upper FET, and a lower FET connected in series to one another. A source electrode of the second upper FET and a drain electrode of the lower FET are connected to each other via an intermediate line. The intermediate line is connected to a U-phase motor coil of a motor via a power line. The first upper FET, the second upper FET, and the lower FET are each provided with a parasitic diode that prevents current from flowing from a battery side to a ground side. A phase opening relay FET is provided on the U-phase power line. A parasitic diode of the phase opening relay FET is provided such that a current is not applied from the U-phase motor coil to the U-phase switching arm.

An electric power steering apparatus that performs an assist control of a steering system, including: at least two respectively independent torque sensors and angle sensors, wherein having a function that respectively calculates steering angles from the torque sensors and the angle sensors to utilize, wherein comparison diagnoses of independent signals are performed and also concurrently individual diagnoses of each individual signal are performed, in a case that it is judged that there is an abnormality in the comparison diagnoses, the angle sensor signals are not used, in a case that it is judged that at least one of the individual diagnoses is abnormal, the angle sensor signal is treated as downgrading, and in a case that it is judged that two or more of the individual diagnoses are abnormal, the angle sensor signals are not used.

Disclosed is an electronic control steering system according to various exemplary embodiments of the present disclosure, which includes: a folding device driven to enable folding of a steering wheel in a driving state of a vehicle an auto folding mode; a first power supply unit supplying power to the folding device; a first angle sensor electrically connected to the first power supply unit; a second power supply unit distinguished from the first power supply unit and supplying power to a second angle sensor; and a control unit controlling steering of the vehicle through the first angle sensor or the second angle sensor, in which when the power supplying from the first power supply unit is interrupted, the control unit may switch the auto folding mode to a manual folding mode so as to manually release the folding of the steering wheel.

A steer-by-wire system includes a steering reaction torque generation device mechanically separated from a turning device for turning wheels and configured to apply a reaction torque to a steering wheel. The steering reaction torque generation device has a duplex configuration including a first system and a second system, each system including a reaction torque motor. When both systems are normal, a control device generates the reaction torque having a normal characteristic by controlling an operation of the reaction torque motor of at least one system. In a case of single failure where one of the systems fails, the control device generates the reaction torque having a first characteristic by controlling an operation of the reaction torque motor of another of the systems. The reaction torque having the first characteristic is different from the reaction torque having the normal characteristic with respect to a same steering angle.

A control section of a steering controller calculates a steer angle which is a turning angle of a first column shaft based on a first detection value detected by a steer angle sensor, and calculates a second shaft turning angle which is a turning angle of a second column shaft based on a second detection value detected by a second shaft rotation angle sensor. A steering torque detection value is calculated based on a third detection value detected by a torque sensor. An abnormality determination part determines abnormalities of the steering torque detection value based on the steer angle and the second shaft turning angle. Thereby, abnormalities of the steering torque detection value are detected without multiplexing the steering torque detection value. Further, if the steering torque detection value is multiplexed, an abnormal steering torque detection value can be specifically identified.

An adaptive front steering system is capable of ensuring steering convenience and driving safety by changing a steering gear ratio in accordance with a driving situation of a vehicle. The adaptive front steering system is implemented as a new type of active front steering (AFS) system in which a hollow motor is applied to a steering column shaft, and a steering gear ratio is changed in accordance with a rotation direction and a rotation amount of a shaft of the hollow motor which is rotated together with an upper shaft.

Restriction values (upper limit and lower limit) for an assist control amount are set individually for each of state amounts including steering torque τ used to compute the assist control amount. A value obtained by summing such restriction values is set as a final restriction value for the assist control amount. Even though the assist control amount with an abnormal value is computed, the assist control amount is restricted to an appropriate value by the final restriction value. In addition, a transition is made from a primary assist control amount which is restricted to a secondary assist control amount computed separately from the primary assist control amount at the timing when a certain time elapses since the assist control amount is restricted. As the steering torque τ is increased, the speed of transition from the primary assist control amount to the secondary assist control amount is increased.

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.

An inverter system failure is detected on the basis of the currents of respective phases detected by a current detection unit when carrying out switching control in accordance with a first drive mode in which all switching elements on a lower-side arm are switched on and all switching elements on an upper-side arm are switched off, and the currents of respective phases detected by the current detection unit when carrying out switching control in accordance with a second drive mode in which all of the switching elements on the upper-side arm are switched on and all of the switching elements on the lower-side arm are switched off.