Electric power steering mode determination and transitioning

Patent metadata

Field	Value
Publication number	US-2018029640-A1
Application number	US-201715656075-A
Country	US
Kind code	A1
Filing date	Jul 21, 2017
Priority date	Jul 26, 2016
Publication date	Feb 1, 2018
Grant date	—

Abstract

Technical solutions are described for facilitating an electric power steering (EPS) system to determine an operating mode of a vehicle that is equipped with the EPS, where the operating mode is indicative of a level of autonomous driving being used by the vehicle. The technical solutions further facilitate detecting a change in the operating mode of the vehicle, and facilitating a transition in computing an assist signal for the EPS system during the transition between the operating modes.

First claim

What is claimed is:

1 . An electric power steering system comprising:
an advance driver assist module configured to:
determine an operation mode that indicates a level of autonomous driving, the operation mode being a first operation mode;
detect a change from the first operation mode to a second operation mode; and
transition performance of the electric power steering system from the first operation mode to the second operation mode.

2 . The electric power steering system of claim 1 , wherein determining the operation mode is based on an amount of intervening handwheel torque measured during operation.

3 . The electric power steering system of claim 1 , wherein detecting the change from the first operation mode to the second operation mode is based on a change in a vehicle configuration, and an amount of intervening handwheel torque, at a vehicle speed that is below a predetermined speed threshold.

4 . The electric power steering system of claim 1 , wherein transitioning the performance comprises:
computing a blend factor for adjusting a first calibration factor of the first operation mode and a second calibration factor of the second operation mode; and computing a third calibration factor based on the first calibration factor, the second calibration factor, and the blend factor.

5 . The electric power steering system of claim 4 , further comprising a control module configured to generate a motor torque command using the third calibration factor.

6 . The electric power steering system of claim 1 , wherein transitioning the performance comprises:
switching off an EPS function.

7 . The electric power steering system of claim 1 , wherein the first operation mode is one of a human operator mode or a hybrid mode and the second operation mode is an autonomous mode.

8 . The electric power steering system of claim 1 , wherein the first operation mode is a human operator mode and the second operation mode is a hybrid mode.

9 . The electric power steering system of claim 1 , wherein the first operation mode is a hybrid mode and the second operation mode is a human operator mode.

10 . An advance driver assist module for an electric power steering system, which is configured to:
determine an operation mode that indicates a level of autonomous driving, the operation mode being a first operation mode; detect a change from the first operation mode to a second operation mode; and transition performance of the electric power steering system from the first operation mode to the second operation mode.

11 . The advance driver assist module of claim 10 , wherein determining the operation mode is based on an amount of handwheel torque.

12 . The advance driver assist module of claim 10 , wherein detecting the change from the first operation mode to the second operation mode is based on a change in a vehicle configuration, and an amount of handwheel torque, at a vehicle speed that is below a predetermined speed threshold.

13 . The advance driver assist module of claim 10 , wherein detecting the change from the first operation mode to the second operation mode is based on a request to switch to the second operation mode.

14 . The advance driver assist module of claim 10 , wherein transitioning the performance comprises:
computing a blend factor for adjusting a first calibration factor of the first operation mode and a second calibration factor of the second operation mode; and computing a third calibration factor based on the first calibration factor, the second calibration factor, and the blend factor.

15 . The advance driver assist module of claim 14 , further comprising a control module configured to generate a motor torque command using the third calibration factor.

16 . A method for providing assist signal to an electric power steering system, the method comprising:
determining an operation mode of the electric power steering system, the operation mode indicates a level of autonomous driving of a vehicle equipped with the electric power steering system, wherein the operation mode is a first operation mode; detecting a change from the first operation mode to a second operation mode; and transitioning performance of the electric power steering system from the first operation mode to the second operation mode.

17 . The method of claim 16 , wherein determining the operation mode is based on an amount of handwheel torque.

18 . The method of claim 16 , wherein detecting the change from the first operation mode to the second operation mode is based on a change in a vehicle configuration, and an amount of handwheel torque, at a vehicle speed that is below a predetermined speed threshold.

19 . The method of claim 16 , wherein transitioning the performance comprises:
computing a blend factor for adjusting a first calibration factor of the first operation mode and a second calibration factor of the second operation mode; and computing a third calibration factor based on the first calibration factor, the second calibration factor, and the blend factor.

20 . The method of claim 16 , further comprising:
in response to receiving a sensor failure indication, bypassing a fault response associated with the sensor failure in response to the electric power steering system being operated in the first operation mode, which is an autonomous mode.

Assignees

• Steering Solutions Ip Holding

Inventors

• Otto Jeffrey M
• Ramanujam Rangarajan
• Sainath Bhuvanesh

Classifications

• B62D5/0463

  calculating assisting torque from the motor based on driver input · CPC title

• B62D15/025 Primary

  Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation (B62D1/28 takes precedence) · CPC title

• G05D1/021

  specially adapted to land vehicles · CPC title

• B62D6/08

  responsive only to {driver} input torque · CPC title

• B62D1/286 Primary

  Systems for interrupting non-mechanical steering due to driver intervention · CPC title