Steering control system for trailers

• US 5,558,350 A
• Filed: 02/15/1994
• Issued: 09/24/1996
• Est. Priority Date: 05/21/1991
• Status: Expired due to Fees

• Current Assignee: University of Utah Research Foundation (State of Utah)
• Original Assignee: University of Utah Research Foundation (State of Utah)
• Inventors: Vincent, R. Scott, Kimbrough, Scott S.
• Primary Examiner(s): BOEHLER, ANNE MARIE M
• Application Number:
  US08/197,010
• Time in Patent Office: 952 Days
• Field of Search: 280/432, 280/419, 280/420, 280/422, 280/426, 280/455.1, 280/459, 280/506, 280/511, 340/870.38, 340/431, 340/687, 324/609, 324/714, 73/1 E
• US Class Current: 280/426
• CPC Class Codes: B60D 1/06 Ball-and-socket hitches , e.g. constructional details, auxiliary devices, their arrangement on the vehicle
• CPC Class Codes: B60D 1/58 Auxiliary devices
• CPC Class Codes: B60D 1/62 involving supply lines, electric circuits, or the like
• CPC Class Codes: B60T 2230/06 Tractor-trailer swaying
• CPC Class Codes: B60T 2260/02 Active Steering, Steer-by-Wire
• CPC Class Codes: B62D 13/025 the pivoted movement being initiated by the coupling means between tractor and trailer
• CPC Class Codes: B62D 13/04 for individually-pivoted wheels

Abstract

An angle sensor for measuring an angle θ between two rigid bodies rotatably joined at a joint. The angle sensor includes an indicator disk, an anchor strap and a mechanism for reading the indicator disk. Our invention also includes forward and backward motion steering control systems which can employ the angle sensor as a hitch angle sensor to measure the hitch angle between a tow vehicle and a trailer.

Claims

1. A hitch angle sensor assembly for measuring a hitch angle θ

between a tow vehicle having a joint and a trailer rotatably joined to the tow vehicle at the joint, said tow vehicle having an XYZ coordinate system and said trailer having an xyz coordinate system, said hitch angle sensor assembly comprising;

(a) a hitch ball having a shaft at its first end, a ball at its second end, and a channeled area located between said first and second ends, said channeled area comprising antifriction material, and said hitch ball being installable on a receiver,

(b) an angle indicator having an outer angle indicator disk and an inner receptacle, said outer angle indicator disk having an opening to permit said inner receptacle to be placed adjacent said channeled area, said inner receptacle comprising antifriction material and being configured so that said inner receptacle can rotate about said channeled area and about the Z axis during a change in hitch angle θ

, said outer angle indicator disk being configured to indicate a hitch angle θ

,

(c) an elongate strap having a first end and a second end, said elongate strap first end being connected to said angle indicator and said elongate strap second end being connectable to a trailer tongue, said strap being rigid in the xy plane in order to facilitate accurate measurement of a hitch angle θ

, and said strap being more rigid in the xy plane than in either the xz or yz planes, and

(d) a sensor adapted to read a hitch angle θ

from said outer angle indicator ring;

wherein said strap and angle indicator are constructed so that they are capable of only rotating about the Z-axis;

wherein said strap is flexible in bending about the y-axis, thereby allowing pitching movements to occur between the tow vehicle and the trailer without binding and without causing rotation of said angle indicator about the Z-axis;

wherein said strap is flexible in twisting about the x-axis thereby allowing rolling movements between the tow vehicle and the trailer to occur without binding and without causing rotation of said indicator disk about the Z-axis;

wherein said strap is rigid about the z-axis; and

wherein said strap causes said indicator disk to return to a θ

=0 position whenever the x-axis lies in the XZ plane.

2. A hitch angle sensor assembly as recited in claim 1 wherein said angle indicator is C-shaped.

3. A hitch angle sensor assembly for measuring a hitch angle θ

between a tow vehicle having a joint and a trailer rotatably joined to the tow vehicle at the joint, said tow vehicle having an XYZ coordinate system and said trailer having an xyz coordinate system, said hitch angle sensor assembly comprising;

(a) a hitch ball having a shaft at its first end and a ball at its second end,

(b) a cylindrical spacer having an inner orifice and an outer surface, said inner orifice being of a physical configuration that it is installable about said shaft,

(c) an angle indicator having an outer angle indicator disk and a circular inner orifice, said circular inner orifice comprising antifriction material and being configured so it is installable about the outer surface of said cylindrical spacer so that said angle indicator can rotate about the Z-axis during a change in hitch angle θ

, said outer angle indicator disk being configured to indicate a hitch angle θ

,

(d) an elongate strap having a first end and a second end, said elongate strap first end being connected to said angle indicator and said elongate strap second end being connectable to a trailer tongue, said strap second end having a slot in it to permit said strap to slide with respect to a trailer tongue to which it is attached in order to accomodate pitching movements between a tow vehicle and a trailer, and said strap being rigid in the xy plane in order to facilitate accurate measurement of a hitch angle θ

, and

(e) a sensor adapted to read a hitch angle θ

from said outer angle indicator disk;

wherein said strap and angle indicator are constructed so that said angle indicator is capable of rotating only about the Z-axis;

wherein said strap is flexible in bending about the y-axis thereby allowing pitching movements between the trailer and the tow vehicle to occur without binding and without causing rotation of said indicator disk about the Z-axis;

wherein said strap is flexible in twisting about the x-axis thereby allowing rolling movements between the trailer and the tow vehicle to occur without binding and without causing rotation of said indicator disk about the Z-axis;

wherein said strap is rigid about the z-axis; and

wherein said strap causes said indicator disk to return to a θ

=0 position whenever the x-axis lies in the XZ plane.