Methods and apparatus to determine rack force are disclosed. An example apparatus includes a rack to couple to a steering knuckle of a vehicle, a ball nut engaged with the rack, a first ring gear coupled to the ball nut, a first pinion fixed to a motor, the first pinion engaged with the first ring gear, the motor to rotate the ball nut to move the rack, a motor encoder to detect a rotation of the first pinion, a second ring gear coupled to the ball nut, and a sensor fixed to a second pinion, the second pinion engaged with the second ring gear, the second pinion to rotate as the second ring gear rotates, the sensor to detect a rotation of the second pinion, the rotation of the second pinion and the rotation of the first pinion corresponding to a force on the rack.

A driving support ECU initializes a target trajectory calculation parameter at a start of LCA; calculates, based on the target trajectory calculation parameter, a target trajectory function representing a target lateral position which is a target position of an own vehicle in a lane width direction in accordance with an elapsed time from the start of LCA; calculates a target control amount based on the target trajectory function; when a steering operation by a driver has been detected, again initializes the target trajectory calculation parameter; and recalculates the target trajectory function based on the target trajectory calculation parameter.

A driving support ECU initializes a target trajectory calculation parameter at a start of LCA; calculates, based on the target trajectory calculation parameter, a target trajectory function representing a target lateral position which is a target position of an own vehicle in a lane width direction in accordance with an elapsed time from the start of LCA; calculates a target control amount based on the target trajectory function; when a steering operation by a driver has been detected, again initializes the target trajectory calculation parameter; and recalculates the target trajectory function based on the target trajectory calculation parameter.

A steering control device 10 is equipped with: a first specification unit 121 for specifying an expected travel position where a vehicle is expected to travel in the traffic lane in which the vehicle is travelling; a second specification unit 122 for specifying information about the weight of the vehicle; an adjustment unit 123 for adjusting the expected travel position in the vehicle-widthwise direction on the basis of the expected travel position of the vehicle and the weight information; and a steering control unit 124 for controlling steering on the basis of the adjusted expected travel position.

One or more embodiments are described for facilitating a vision based active steering system. An example steering system includes a handwheel actuator that generates a first feedback torque based on road surface forces at a roadwheel. The steering system further includes a controller that receives, from an image-based system, a control signal indicative of a type of road surface based on an image of the road surface. Further, in response, the controller adjusts one or more parameters of the handwheel actuator to generate a second feedback torque based on the road surface forces at the roadwheel.

One or more embodiments are described for facilitating a vision based active steering system. An example steering system includes a handwheel actuator that generates a first feedback torque based on road surface forces at a roadwheel. The steering system further includes a controller that receives, from an image-based system, a control signal indicative of a type of road surface based on an image of the road surface. Further, in response, the controller adjusts one or more parameters of the handwheel actuator to generate a second feedback torque based on the road surface forces at the roadwheel.

A vehicle control method for controlling a vehicle using a vehicle control apparatus includes: a sensor configured to detect a state outside a subject vehicle; and a control device. The vehicle control method includes: executing control of recovering a travel trajectory of the subject vehicle to a target trajectory, as ordinary control, by giving a steering amount in a lateral direction with respect to a travel lane of the subject vehicle; using detection data of the sensor to determine whether or not another vehicle is traveling in an adjacent lane to the travel lane of the subject vehicle; and when determining that the other vehicle is traveling in the adjacent lane ahead of the subject vehicle, increasing a response of the steering amount to a higher response than that in the ordinary control, before the subject vehicle passes the other vehicle.

A steering control device includes a processor. The processor is configured to calculate an axial force component and a restriction reaction force. The processor is also configured to calculate target reaction torque based on a reaction force component obtained by adding the axial force component and the restriction reaction force. The processor is also configured to limit an absolute value of the reaction force component to a limit value or less, the limit value being such a value that the reaction force component does not become too large.

A steering control device includes a processor. The processor is configured to calculate an axial force component and a restriction reaction force. The processor is also configured to calculate target reaction torque based on a reaction force component obtained by adding the axial force component and the restriction reaction force. The processor is also configured to limit an absolute value of the reaction force component to a limit value or less, the limit value being such a value that the reaction force component does not become too large.

Technical solutions are described for mitigating traction steer using an electric power steering system (EPS). A control system for a power steering system including a processor and memory are provided. The memory includes instructions that, when executed by the processor, cause the processor to generate a motor command as a function of a handwheel velocity, and to modify the motor command based upon a traction torque signal. A method for controlling a power steering system is also provided. The method includes generating a motor command as a function of a handwheel velocity; modifying the motor command based upon a traction torque signal; and applying the motor command to an actuator of the power steering system.