Abstract: A steer-by-wire steering system including: an operation member to be operated by a driver; a reaction force applying device configured to apply an operation reaction force to the operation member; a steering device including a steering motor that is an electric motor as a drive source and configured to steer a wheel; and a controller configured to control the reaction force applying device and the steering device, wherein the controller determines the operation reaction force including a steering-current-dependent component which is a component based on a current supplied to the steering motor and a steering-speed-dependent correction component to reduce the steering-current-dependent component based on a steering speed; and wherein the controller determines the steering-speed-dependent correction component such that when the steering speed exceeds a set speed, the steering-speed-dependent correction component is not larger than a value at the set speed.

Abstract: A steering control device includes: a target rotation angle calculation circuit that calculates a target rotation angle of a shaft; an offset angle calculation circuit that calculates an offset angle relative to the target rotation angle; a final target rotation angle calculation circuit that calculates a final target rotation angle of the shaft; and a feedback control circuit that executes feedback control that adapts a real angle to the final target rotation angle. The offset angle calculation circuit calculates an estimated rotation angle deviation based on a value of a current of a turning motor immediately before a specific event occurs, and calculates the offset angle by subtracting the real angle and the estimated rotation angle deviation from the target rotation angle.

Abstract: A steering system of a steer-by-wire type, provided in a vehicle, includes a turning device configured to turn wheels of the vehicle, a reaction force device configured to apply a reaction force to a steering operation member operable by a driver, and a controller configured to control the reaction force. The controller is configured to control the reaction force based on a phase-adjusted deviation. The phase-adjusted deviation is a deviation between an actual steering angle and a target steering angle. A phase in the phase-adjusted deviation has been adjusted, and the actual steering angle is an actual steering angle of the wheels. The target steering angle is a target value of the steering angle of the wheels.

Abstract: A reaction force actuator applies, during normal operation, a steering reaction force, which rapidly increases upon approaching an upper limit of a virtual steering range, to a steering wheel. During rapid steering in which a turning angle velocity is greater than or equal to a predetermined value and a turning follow delay is greater than or equal to a predetermined value, the reaction force actuator applies a steering reaction force to the steering wheel based on an upper limit corresponding to a narrower virtual steering range.

Abstract: A steering control device calculates a target angle of a shaft that rotates in conjunction with a turning operation of a turning wheel that is isolated from dynamic power transmission with a steering wheel, depending on a steering state of the steering wheel, and executes a feedback control to cause an actual angle to follow the target angle, for controlling electricity supply to a turning motor to turn the turning wheel, the steering control device including: a first processing unit to execute a process to alter the target angle independently of the steering state of the steering wheel; and a second processing unit to calculate a turning state amount for a guide monitor function to assist traveling of a vehicle, by reducing or removing an influence of an alteration of the target angle on the actual angle of the shaft.

Abstract: A steering control device includes: a target rotation angle calculation circuit that calculates a target rotation angle of a shaft; an offset angle calculation circuit that calculates an offset angle relative to the target rotation angle; a final target rotation angle calculation circuit that calculates a final target rotation angle of the shaft; and a feedback control circuit that executes feedback control that adapts a real angle to the final target rotation angle. The offset angle calculation circuit calculates an estimated rotation angle deviation based on a value of a current of a turning motor immediately before a specific event occurs, and calculates the offset angle by subtracting the real angle and the estimated rotation angle deviation from the target rotation angle.

Abstract: A steering control device is configured to control a steering device. The steering device includes a turning shaft and a turning motor. The turning shaft is configured to turn a turning wheel of a vehicle. Dynamic power transmission between the turning shaft and a steering wheel is separated. The steering control device includes a processing device. The processing device is configured to control drive of the turning motor depending on a steering state of the steering wheel. The processing device is configured to execute a lock process based on a command from an exterior, in a state where the steering device is equipped in the vehicle. The lock process is a process of driving the turning motor such that the position of the turning shaft is kept at a particular position.

Abstract: A steer-by-wire steering system includes a controller configured to execute a steering control process and a determining process of determining a converted operation amount by converting an actual wheel steering amount to an operation amount of an operation member based on an inverse of a steering gear ratio. In the determining process, when the steering gear ratio abruptly changes, the controller converts a gap of the converted operation amount generated at a time point of occurrence of the abrupt change to a gap of the wheel steering amount to grasp a converted steering amount offset value. While gradually decreasing the converted steering amount offset value, the controller thereafter re-converts the converted steering amount offset value to the gap of the converted operation amount based on the inverse of the steering gear ratio to determine a converted operation amount correction value and corrects the converted operation amount based on the value.

Abstract: A vehicle control system for a steer-by-wire vehicle executes: driving assist control that assists driving of the vehicle; and conjunction reaction force control that applies a steering reaction force component to a steering wheel in conjunction with vehicle turning caused by the driving assist control. A driver turn angle is a target turn angle corresponding to a steering angle of the steering wheel, and a first system turn angle is a target turn angle required by the driving assist control. In the conjunction reaction force control, a second system turn angle is acquired by adjusting the first system turn angle according to a driver's steering intention such that the difference between the system turn angle and the driver turn angle becomes smaller. Then, a steering reaction force component is applied in a direction of reducing a difference between the driver turn angle and the second system turn angle.

Abstract: A steering device includes a turning shaft, a turning motor, and a control device that controls the turning motor such that an angle capable of being converted into a turning angle of a turning wheel follows a target angle that is calculated depending on a steering state of a steering wheel. The control device executes a correction process of correcting the target angle. The control device corrects the target angle such that the degree of an increase in the target angle is slower as the target angle approaches a limit value of an angle region, when the target angle increases toward the limit value of the angle region in either of a vehicle stop state or an extremely low speed state.

Abstract: A vehicle control system controls a steer-by-wire type vehicle. The vehicle control system executes: reaction force control that applies a steering reaction force to a steering wheel; and driving assist control that assists driving of the vehicle. The reaction force control includes road information transmission control that applies a steering reaction force component corresponding to an oscillation caused by road surface unevenness to the steering wheel. The vehicle control system deactivates the road information transmission control when a deactivation condition is satisfied. The deactivation condition is that the driving assist control is in operation and a steering parameter reflecting a driver's steering intention is less than a threshold. As another example, the deactivation condition is that the driving assist control that vibrates the steering wheel for notifying the driver of a possibility of a lane departure is in operation.

Abstract: A steering control device is configured to control a steering device as a controlled object, the steering device having a structure in which transmission of power between a steering portion and a turning portion is cut off. The steering control device includes a central processing unit. The central processing unit is configured to execute a reduction process in a case where at least either one of a travel state amount and a steering state amount is a state amount indicating that a target turning-corresponding angle does not change. The reduction process is a process of reducing a driving current to be supplied to a turning motor.

Abstract: A reaction force actuator applies, during normal operation, a steering reaction force, which rapidly increases upon approaching an upper limit of a virtual steering range, to a steering wheel. During rapid steering in which a turning angle velocity is greater than or equal to a predetermined value and a turning follow delay is greater than or equal to a predetermined value, the reaction force actuator applies a steering reaction force to the steering wheel based on an upper limit corresponding to a narrower virtual steering range.

Abstract: A turning control device includes a first processor, a second processor, a third processor, and a fourth processor. The first processor calculates a torque command value based on a difference between a target pinion angle and a pinion angle. The second processor calculates a compensation value compensating resistance of a turning mechanism based on a difference between a target pinion angular velocity and a pinion angular velocity. The third processor limits a variation range of the torque command value based on a limit value of the torque command value and limits a variation range of the compensation value based on a limit value of the compensation value. The fourth processor calculates a turning torque command value by subtracting the compensation value from the torque command value. The third processor changes the limit values based on a traveling state of a vehicle.

Abstract: A steering control device calculates a target angle of a shaft that rotates in conjunction with a turning operation of a turning wheel that is isolated from dynamic power transmission with a steering wheel, depending on a steering state of the steering wheel, and executes a feedback control to cause an actual angle to follow the target angle, for controlling electricity supply to a turning motor to turn the turning wheel, the steering control device including: a first processing unit to execute a process to alter the target angle independently of the steering state of the steering wheel; and a second processing unit to calculate a turning state amount for a guide monitor function to assist traveling of a vehicle, by reducing or removing an influence of an alteration of the target angle on the actual angle of the shaft.

Abstract: A thermal acid generator having a high acid generation temperature, and a resist composition using the same.

Abstract: A steer-by-wire steering system includes a controller configured to execute a steering control process and a determining process of determining a converted operation amount by converting an actual wheel steering amount to an operation amount of an operation member based on an inverse of a steering gear ratio. In the determining process, when the steering gear ratio abruptly changes, the controller converts a gap of the converted operation amount generated at a time point of occurrence of the abrupt change to a gap of the wheel steering amount to grasp a converted steering amount offset value. While gradually decreasing the converted steering amount offset value, the controller thereafter re-converts the converted steering amount offset value to the gap of the converted operation amount based on the inverse of the steering gear ratio to determine a converted operation amount correction value and corrects the converted operation amount based on the value.

Abstract: A vehicle control system for a steer-by-wire vehicle executes: driving assist control that assists driving of the vehicle; and conjunction reaction force control that applies a steering reaction force component to a steering wheel in conjunction with vehicle turning caused by the driving assist control. A driver turn angle is a target turn angle corresponding to a steering angle of the steering wheel, and a first system turn angle is a target turn angle required by the driving assist control. In the conjunction reaction force control, a second system turn angle is acquired by adjusting the first system turn angle according to a driver's steering intention such that the difference between the system turn angle and the driver turn angle becomes smaller. Then, a steering reaction force component is applied in a direction of reducing a difference between the driver turn angle and the second system turn angle.

Abstract: A vehicle control system controls a steer-by-wire type vehicle. The vehicle control system executes: reaction force control that applies a steering reaction force to a steering wheel; and driving assist control that assists driving of the vehicle. The reaction force control includes road information transmission control that applies a steering reaction force component corresponding to an oscillation caused by road surface unevenness to the steering wheel. The vehicle control system deactivates the road information transmission control when a deactivation condition is satisfied. The deactivation condition is that the driving assist control is in operation and a steering parameter reflecting a driver's steering intention is less than a threshold. As another example, the deactivation condition is that the driving assist control that vibrates the steering wheel for notifying the driver of a possibility of a lane departure is in operation.

Abstract: A thermal acid generator having a high acid generation temperature, and a resist composition using the same.