All-wheel steering systems
First Claim
1. An all wheel steering system for a vehicle having front wheels with a front wheel angle, rear wheels with a rear wheel angle, and a steering wheel, the front wheel angle being determined by an operator positioning the steering wheel, the rear wheel angle being determined by the system, the system comprising:
- means for sensing a front wheel angle of at least one front wheel,means for communicating the front wheel angle to a controller means, the controller means including a memory containing at least one desired rear wheel angle for each front wheel angle, the desired rear wheel angle being dependant upon the front wheel angle when the front wheel angle exceeds a deadband value ranging from 3°
to 15°
, the desired rear wheel angle is 0°
when the front wheel angle does not exceed the deadband value regardless of vehicle speed the controller means retrieving a desired rear wheel angle based on the front wheel angle from the memory of the controller means,means for sensing an actual rear wheel angle of at least one rear wheel,means for communicating the actual rear wheel angle to the controller means,the controller means comparing the actual rear wheel angle with the desired rear wheel angle, the controller means sending a signal to alter the actual rear wheel angle to a means for controlling the actual rear wheel angle if the actual rear wheel angle differs from the desired rear wheel angle by an amount that is greater than a desired amount.
3 Assignments
0 Petitions
Accused Products
Abstract
A full-time all wheel steering system is provided whereby the rear wheel angle is determined by the front wheel angle and a relational curve, polynomial equation or set of tabulated values. The front wheel angle is measured and the desired rear wheel angle is calculated by a programmable controller. If the desired rear wheel angle is not sufficiently close to the actual rear wheel angle, the controller means sends a signal which results in adjustment of the rear wheel angle. The desired rear wheel angle may be a function of the vehicle speed as well as the front wheel angle. Further, the operator may select from a plurality of relational curves, polynomial equations, tabulated values as well as a plurality of manually selectable modes including an independent rear wheel steering mode. The system is applicable to passenger cars, trucks and tractor-trailer rigs.
93 Citations
31 Claims
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1. An all wheel steering system for a vehicle having front wheels with a front wheel angle, rear wheels with a rear wheel angle, and a steering wheel, the front wheel angle being determined by an operator positioning the steering wheel, the rear wheel angle being determined by the system, the system comprising:
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means for sensing a front wheel angle of at least one front wheel, means for communicating the front wheel angle to a controller means, the controller means including a memory containing at least one desired rear wheel angle for each front wheel angle, the desired rear wheel angle being dependant upon the front wheel angle when the front wheel angle exceeds a deadband value ranging from 3°
to 15°
, the desired rear wheel angle is 0°
when the front wheel angle does not exceed the deadband value regardless of vehicle speed the controller means retrieving a desired rear wheel angle based on the front wheel angle from the memory of the controller means,means for sensing an actual rear wheel angle of at least one rear wheel, means for communicating the actual rear wheel angle to the controller means, the controller means comparing the actual rear wheel angle with the desired rear wheel angle, the controller means sending a signal to alter the actual rear wheel angle to a means for controlling the actual rear wheel angle if the actual rear wheel angle differs from the desired rear wheel angle by an amount that is greater than a desired amount. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A four wheel steering system for a vehicle having a pair of front wheels and at least one pair of rear wheels, the front and rear wheels being steerable, the system comprising:
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means for sensing a front wheel angle of at least one front wheel, means for communicating the front wheel angle to a controller means, the controller means including a memory, means for sensing the speed of the vehicle, means for communicating the speed of the vehicle to the controller, the memory of the controller means containing at least one desired rear wheel angle for each front wheel angle for each speed of the vehicle, the controller means retrieving a desired rear wheel angle based on the front wheel angle and the speed from the memory of the controller means, the desired rear wheel angles being dependant upon the speed of the vehicle and the front wheel angle when the front wheel angle exceeds a deadband value ranging from 3°
to 15°
, the desired rear wheel angle is 0°
when the front wheel angle does not exceed the deadband value regardless of vehicle speed,means for sensing an actual rear wheel angle of at least one rear wheel, means for communicating the actual rear wheel angle to the controller means, the controller means comparing the actual rear wheel angle with the desired rear wheel angle, the controller means sending a signal to alter the actual rear wheel angle to a means for controlling the actual rear wheel angle if the actual rear wheel angle differs from the desired rear wheel angle by an amount greater than a desired amount. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
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24. An all wheel steering system for a tractor-trailer rig, the tractor having at least one pair of front wheels with a front wheel angle, the tractor also including a steering wheel, the trailer having at least one pair of rear wheels that is steerable and having a rear wheel angle, the front wheel angle of the tractor being determined by an operator positioning the steering wheel, the rear wheel angle being determined by the system, the system comprising:
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means for sensing a front wheel angle of at least one front wheel, means for communicating the front wheel angle to a controller means, the controller means including a memory containing at least one desired rear wheel angle for each front wheel angle, the controller means retrieving a desired rear wheel angle based on the front wheel angle from the memory of the controller means, means for sensing an actual rear wheel angle of at least one rear wheel of the pair of rear wheels, means for communicating the actual rear wheel angle to the controller means, the controller means comparing the actual rear wheel angle with the desired rear wheel angle, the controller means sending a signal to alter the actual rear wheel angle to a means for controlling the actual rear wheel angle if the actual rear wheel angle differs from the desired rear wheel angle by an amount that is greater than a desired amount. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31)
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Specification