Steering control system for vehicle

• US 20040148076A1
• Filed: 07/25/2003
• Published: 07/29/2004
• Est. Priority Date: 07/26/2002
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Co. (HP Inc.)
• Original Assignee: Toyoda Koki Kabushiki Kaisha
• Inventors: Kojo, Takahiro, Nakatsu, Masatoshi, Kawamuro, Junji, Kodama, Kazumasa
• Granted Patent: US 6,801,840 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• CPC Class Codes: B62D 15/0215 by measuring on the steering column
• CPC Class Codes: B62D 5/008 Changing the transfer ratio between the steering wheel and the steering gear by variable supply of energy, e.g. by using a superposition gear
• CPC Class Codes: G01D 5/2497 Absolute encoders G01D5/2454 takes precedence

Abstract

A angle sensor 103 identifies a angle phase of a rotatable member based on a kind of an identified pattern of the angle phase to detect an angular position of a steering shaft driven by a motor 6. A steering controller 100 identifies a rotational direction based on an identified pattern output of the angle and performs a sampling of the pattern output at a predetermined interval, identifies an order of combination order of the identified pattern of an angle phase in a first sampling and a second sampling following to the first sampling, and determines a pattern exchange number with the rotational direction from the order in the first sampling to the order in the second sampling. The steering controller 100 adds a number corresponding to the pattern exchange number to a counting number when the rotational direction is plus and decrease a number corresponding to the pattern exchange number from the counting number when the rotational direction is minus in order to identify the angular position of the steering shaft by the counted number.

Claims

1. A steering control system for a vehicle determining a steering angle sent to a steering shaft according to an operation angle of a handle shaft and a driving stage of the vehicle, and rotating the steering shaft by an actuator to create the steering angle, comprising:

an angle detector identifying a phase of a rotation angle of said shaft to determine an angular position of said steering shaft; and

a steering controller receiving a pattern output of said identified angle phase from said angle detector, wherein

said steering controller identifies a rotational direction of said angle detector based on said pattern output, performs a sampling of said pattern output at a predetermined interval, identifies an order of combination order of said identified pattern of said angle phase in a first sampling and a second sampling following to said first sampling, and determines a pattern exchange number with said rotational direction,

said steering controller adds a number corresponding to said pattern exchange number to a counting number when said rotational direction is plus and decrease a number corresponding to said pattern exchange number from said counting number when said rotational direction is minus, and

said steering controller has an angular position counter of steering shaft registers said angular position of steering shaft by said counting number.

2. The steering control system for the vehicle according to claim 1, wherein

said steering controller includes a counter control means performing an prohibiting operation prohibiting said operation of adding or decreasing said pattern exchange number to or from said counting number in said angular position counter of steering shaft when an absolute number of said pattern exchange number is larger than a reference pattern exchange number.

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

said steering control system for the vehicle further comprising an angle velocity detecting member to calculating an angle velocity of a rotatable member of said angle sensor, wherein

said counter control means changes a set condition being set to perform said count prohibiting operation according to said calculated angle velocity.

4. The steering control system for the vehicle according to claim 3, wherein

said counter control means set largely said pattern reference number for performing said count prohibiting operation according to an exceeding number of said angle velocity.

5. The steering control system for the vehicle according to claim 4, wherein

said steering controller sets a first angle velocity scope and a second angle velocity scope located at the side of greater angle velocity next to said first angle velocity scope,

said reference pattern exchange number is set a predetermined first value at said first angle velocity scope and is set a predetermined second value larger than said first value at said second angle velocity scope.

6. The steering control system for the vehicle according to one of claim 3 to claim 5, wherein

said count control means does not perform said count prohibiting operation independent to said pattern exchange number when said angle velocity exceeds over a predetermined reference angle velocity.

7. The steering control system for the vehicle according to claim 6, wherein

said steering controller sets a first angle velocity scope, a second angle velocity scope located at the side of greater angle velocity next to said first angle velocity scope and a third angle velocity scope located at the side of greater angle velocity next to said second angle velocity scope,

said reference pattern exchange number is set a predetermined first value at said first angle velocity scope and is set a predetermined second value larger than said first value at said second angle velocity scope, and

said count prohibiting operation is not performed independently to said pattern exchange number at said third angle velocity scope.