VEHICLE STEERING SYSTEM

• US 20070288142A1
• Filed: 06/06/2007
• Published: 12/13/2007
• Est. Priority Date: 06/07/2006
• Status: Active Grant

• Current Assignee: Jtekt Corporation (Toyota Motor Corporation)
• Original Assignee: Jtekt Corporation (Toyota Motor Corporation)
• Inventors: Yamanaka, Kosuke, Arima, Masanori, Ishihara, Atsushi, Maeda, Shingo, Maeda, Daisuke, Maeda, Naoki, KOUCHI, Tatsuma
• Granted Patent: US 7,516,003 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• CPC Class Codes: B62D 1/286 Systems for interrupting non-mechanical steering due to driver intervention
• CPC Class Codes: B62D 15/0285 Parking performed automatically

Abstract

A vehicle steering system includes: a steering actuator that imparts a steering force to a steering mechanism of a vehicle; an automatic steering controller that performs an automatic steering control by controlling the steering actuator; a driving state detector that detects a driving state of the vehicle during the automatic steering control; a threshold value setting unit that variably sets a threshold value for permitting an intervention in the automatic steering control; and an automatic steering intervention unit that intervenes in the automatic steering control based on a threshold value set by the threshold value setting unit.

Claims

1. A vehicle steering system comprising:

a steering actuator (M) for imparting a steering force to a steering mechanism (1) of a vehicle;

an automatic steering controller (22) for performing an automatic steering control by controlling the steering actuator;

a driving state detector (11, 25) for detecting a driving state of the vehicle during the automatic steering control;

threshold value setting means (S1, S2, S5;

S11) for variably setting a threshold value (TH) for permitting an intervention in the automatic steering control based on the driving state; and

automatic steering intervention means (24, 29, S3, S4, S6, S7;

S12, S13) for intervening in the automatic steering control based on a threshold value set by the threshold value setting means.

2. The vehicle steering system according to claim 1, further comprising:

a control member associated with the steering mechanism; and

a torque detector that detects a manipulating torque applied to the control member,

wherein the threshold value setting means variably sets a torque threshold value for permitting an intervention in the automatic steering control, and

the automatic steering intervention means intervenes in the automatic steering control when the manipulating torque detected by the torque detector exceeds the torque threshold value set by the threshold value setting means.

3. The vehicle steering system according to claim 2, wherein

the driving state detector includes an operation speed detector (25) for detecting an operation speed of the control member, and

the threshold value setting means determines the torque threshold value so as to become smaller as the operation speed detected by the operation speed detector becomes faster.

4. The vehicle steering system according to claim 3, wherein the automatic steering intervention means includes an operation speed limiting means (29) for intervening in the automatic steering control in the case that the operation speed detected by the operation speed detector exceeds a predetermined speed threshold value and limiting the operation speed of the control member to be equal to or lower than the speed threshold value.

5. The vehicle steering system according to claim 4, wherein the operation speed limiting means intervenes in the automatic steering control and limits the operation speed of the control member to be equal to or lower than the speed threshold value when the manipulating torque detected by the torque detector exceeds the torque threshold value set by the threshold value setting means in the case that an operation speed detected by the operation speed detector exceeds the speed threshold value.

6. A vehicle steering system according to claim 4 or 5, wherein the automatic steering intervention means cancels the automatic steering control when the manipulating torque detected by the torque detector exceeds the torque threshold value set by the threshold value setting means in the case that the operation speed detected by the operation speed detector is lower than the speed threshold value.