US-12617455-B2 - Systems and methods for controlling vehicle travel

US12617455B2US 12617455 B2US12617455 B2US 12617455B2US-12617455-B2

Abstract

A rear wheel steering system for a vehicle selectively controls a vehicle after front wheel steering is compromised. The rear wheel steering control system includes a rear wheel steering electronic control unit (ECU) and a stability control module. The rear wheel steering ECU electrically communicates with a front wheel steering ECU used to control the front wheel steering. The front wheel steering ECU is coupled to a front wheel steering angle sensor that detects a measured front wheel steering angle and transmits the measured front wheel steering angle to the rear wheel steering ECU. The stability control module is electrically coupled to the rear wheel steering ECU and receives the vehicle yaw data and vehicle speed data. The rear wheel steering ECU and/or stability control module estimates a front wheel steering angle for the vehicle for use in selectively steering the vehicle.

Inventors

Michael P. Hullihan
Casey R. Burkhart
Matthew DJ Taylor
Joshua D. Pritchard

Assignees

HONDA MOTOR CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20240326

Claims (20)

1 . A rear wheel steering system for a vehicle having front wheel steering, said rear wheel steering system comprising: a rear wheel steering electronic control unit (ECU) configured to selectively control the rear wheels of the vehicle, said rear wheel steering ECU in electrical communication with a front wheel steering ECU used to control the front wheel steering of the vehicle, the front wheel steering ECU is communicatively coupled to a front wheel steering angle sensor configured to detect a measured front wheel steering angle of the vehicle front wheels that is transmitted to said rear wheel steering ECU; and a stability control module electrically coupled to said rear wheel steering ECU, said stability control module receives vehicle yaw data and vehicle speed data, at least one of said stability control module and said rear wheel steering ECU configured to estimate a front wheel steering angle for the vehicle, said rear wheel steering ECU selectively controls steering of the vehicle rear wheels based at least on the estimated front wheel steering angle for the vehicle, and said rear wheel steering ECU limits at least one of a rear steering stroke and a rear steering stroke speed when controlling the rear wheel steering angle based on the estimated front wheel steering angle.
2 . The system of claim 1 , wherein, when the measured front steering angle is received at said rear wheel steering ECU, said rear wheel steering ECU selectively controls the rear wheel steering angle based on the measured front steering angle, and wherein, when the measured front steering angle is not received at the rear wheel steering ECU, said rear wheel steering ECU selectively controls the rear wheel steering angle based on the estimated steering angle.
3 . The system of claim 1 wherein at least one of said rear wheel steering ECU and said stability control module uses a bicycle model in conjunction with data received from at least one sensor to estimate the front wheel steering angle for the vehicle.
4 . The system of claim 1 wherein at least one of said rear wheel steering ECU and said stability control module is further configured to limit at least one of the rear steering stroke and the rear steering stroke speed based upon the vehicle speed data.
5 . The system of claim 4 wherein at least one of said rear wheel steering ECU and said stability control module is further configured to control movement of the vehicle rear wheels only after a pre-defined yaw threshold for the vehicle has been exceeded.
6 . The system of claim 1 wherein the rear wheel steering ECU facilitates reducing the steering effort of a driver of the vehicle when the vehicle front wheel steering has been compromised and the vehicle is being guided to a side of the road.
7 . The system of claim 1 further comprising a supplemental restraint system (SRS) module electrically coupled to at least one of the stability control module and the rear wheel steering ECU, said SRS module configured to generate the vehicle yaw data and the vehicle speed data.
8 . A vehicle steering system comprising: a front wheel steering electronic control unit (ECU) configured to selectively control front wheel steering of the vehicle, said front wheel steering ECU coupled to a steering angle sensor that detects a measured front wheel steering angle for the vehicle; a rear wheel steering ECU communicatively coupled to said front wheel ECU and configured to receive the front wheel steering angle from the front wheel ECU to facilitate coordinated steering of the vehicle rear wheels with the vehicle front wheels; and a stability control module electrically coupled to said rear wheel steering ECU, said stability control module receives vehicle yaw data and vehicle speed data, at least one of said rear wheel steering ECU and said stability control module configured to estimate a front wheel steering angle for the vehicle, said rear wheel steering ECU selectively controls steering of the vehicle rear wheels based at least on the estimated front wheel steering angle, and said rear wheel steering ECU limits at least one of a rear steering stroke and a rear steering stroke speed when controlling the rear wheel steering angle based on the estimated front wheel steering angle, when the front wheel steering has been compromised.
9 . The vehicle steering system of claim 8 , wherein the measured front steering angle is received at said rear wheel steering ECU, said rear wheel steering ECU selectively controls the rear wheel steering angle based on the measured front steering angle, and wherein, when the measured front steering angle is not received at the rear wheel steering ECU, said rear wheel steering ECU selectively controls the rear wheel steering angle based on the estimated front wheel steering angle.
10 . The vehicle steering system of claim 8 wherein at least one of said rear wheel steering ECU and said stability control module uses detected yaw data for the vehicle and detected speed data for the vehicle in combination with a bicycle model to estimate the front wheel steering angle for the vehicle.
11 . The vehicle steering system of claim 9 further comprising a supplemental restraint system (SRS) module, and at least one of a vehicle yaw sensor and a vehicle speed detector, said SRS module electrically coupled to at least one of the stability control module and the rear wheel steering ECU, said SRS module configured to generate the vehicle yaw and the vehicle speed data.
12 . The vehicle steering system of claim 8 wherein at least one of said rear wheel steering ECU and said stability control module is further configured to limit at least one of the rear steering stroke and the rear steering stroke speed based upon the vehicle speed data.
13 . The vehicle steering system of claim 12 wherein said rear wheel steering ECU facilitates reducing steering effort to a driver of the vehicle after the front wheel steering has been compromised.
14 . The vehicle steering system of claim 13 wherein said rear wheel steering ECU is only operable when the front wheel steering has been compromised after a pre-defined yaw threshold for the vehicle has been exceeded.
15 . The vehicle steering system of claim 9 wherein said rear wheel steering ECU facilitates reducing an overall weight of the vehicle.
16 . The vehicle steering system of claim 9 wherein said front wheel steering ECU is facilitates controlling front wheel steering through a steer-by-wire application, said rear wheel steering ECU facilitates reducing a wiring complexity of the vehicle.
17 . A method of controlling movement of a vehicle after front wheel steering of the vehicle has been compromised, said method comprising: generating an estimated front wheel steering angle after the front wheel steering has been compromised; transmitting the estimated front wheel steering angle to a rear wheel steering electronic control unit configured to selectively control the rear wheel steering; and selectively steering the rear wheels of the vehicle based on the estimated front wheel steering angle; and limiting at least one of a rear steering stroke and a rear steering stroke speed when controlling the rear wheel steering angle based on the estimated front wheel steering angle.
18 . A method in accordance with claim 17 wherein generating an estimated front wheel steering angle after the front wheel steering has been compromised further comprises: detecting a yaw of the vehicle and a speed of the vehicle; and using a bicycle model to correlate the vehicle yaw and the vehicle speed to generate the estimated front wheel steering wheel angle.
19 . A method in accordance with claim 18 wherein selectively steering the rear wheels of the vehicle further comprises selectively steering the rear wheels of the vehicle only after a pre-defined yaw threshold for the vehicle has been exceeded.
20 . A method in accordance with claim 18 wherein selectively steering the rear wheels of the vehicle further comprises selectively steering the rear wheels of the vehicle without receiving a detected front wheel steering angle.

Description

BACKGROUND The field of the disclosure relates generally to steering control technologies used with vehicles and, more particularly to methods and systems for controlling vehicle travel when the front wheel steering of a vehicle is compromised. At least some known vehicles are equipped with a front axle or wheel steering system and an automatic rear axle or wheel steering system. When such vehicles are traveling at lower speeds, when activated, the rear wheel steering system can enhance maneuverability and can enable tighter radius turns, and may assist in parallel parking, for example. However, when such vehicles are traveling at higher speeds, such as along an interstate, cornering radii are typically much larger and the rear wheel steering system may provide different assistance to the vehicle. For example, at higher traveling speeds, the rear wheel steering may provide automatic lateral steering control assist to facilitate lane centering, controlled lane changing, lane following, and/or collision avoidance purposes, for example. Steering a vehicle is generally considered a critical function, so much so that at least some vehicles include rear wheel steering to assist in guiding, i.e., limping, a vehicle to the shoulder of a road if the front wheel steering system becomes compromised. In vehicles having front and rear wheel steering systems, rear wheel steering requires a front wheel steering angle signal to function. As such. at least some known vehicles include redundancy in the front and rear wheel steering systems. For example, in at least some vehicles a steer-by-wire system is used to control steering of the front wheels, and the rear wheel steering is controlled through a system of multiple steering actuators and/or multiple redundant sensors. However, the multiple redundant components increase the cost, weight, and complexity of the steering systems. Accordingly, it is desirable to have systems and methods that facilitate controlling a vehicle with the use of rear wheel steering when the front wheel steering system is compromised, without requiring the use of redundant and complex steering components. This Background section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, these statements are to be read in this light, and not as admissions of prior art. BRIEF DESCRIPTION In one aspect, a rear wheel steering system for a vehicle having front wheel steering is provided. The rear wheel steering control system includes a rear wheel steering electronic control unit (ECU) and a stability control module. The rear wheel steering ECU is configured to selectively control the rear wheels of the vehicle. The rear wheel steering ECU is in electrical communication with a front wheel steering ECU used to control the front wheel steering of the vehicle. The front wheel steering ECU is coupled to a front wheel steering angle sensor configured to detect and transmit a front wheel steering angle of the vehicle front wheels to the rear wheel steering ECU. The stability control module is electrically coupled to the rear wheel steering ECU. The stability control module receives the vehicle yaw data and vehicle speed data. The stability control module and/or the rear wheel steering ECU is configured to estimate a front wheel steering angle for the vehicle, for use in selectively controlling steering of the vehicle rear wheels. In another aspect a vehicle steering system is provided. The vehicle steering system includes a front wheel steering ECU, a rear wheel steering ECU, and a stability control module. The front wheel steering ECU is configured to selectively control front wheel steering of the vehicle. The front wheel steering ECU is coupled to a steering angle sensor that detects a front wheel steering angle for the vehicle. The rear wheel steering ECU is coupled to the front wheel ECU and receives the detected front wheel steering angle from the front wheel ECU to facilitate coordinated steering of the vehicle rear wheels with the vehicle front wheels. The stability control module is electrically coupled to the rear wheel steering ECU, and receives the vehicle yaw data and the vehicle speed data. The stability control module and/or the rear wheel steering ECU is configured to estimate a front wheel steering angle for the vehicle, for use in selectively controlling steering of the vehicle rear wheels when the front wheel steering has been compromised. In a further aspect, a method of controlling movement of a vehicle after front wheel steering of the vehicle has been compromised is provided. The method includes generating an estimated front wheel steering angle after the front wheel steering has been com