Vehicle velocity sensing apparatus and method
First Claim
1. A velocity determining apparatus for a vehicle, said vehicle having at least one surface engaging wheel, comprising:
- resolver means for producing a rotation angle rate signal having a value responsive to the angular rotation rate of said wheel, said resolver means having a shaft rotatably connected to said wheel;
converter means for receiving said rotation angle rate signal and producing a rotation rate pulse signal having a pulse duration responsive to said rotation angle rate signal;
clock means for substantially continuously producing a clock pulse signal having a predetermined frequency;
counter means for receiving said rotation rate pulse signal and said clock pulse signal and controllably producing a numeric time signal corresponding to the number of clock pulses received from said clock means over the duration of a predetermined portion of said rotation rate pulse signal and a status signal in response to termination of said predetermined portion of said rotation rate pulse signal; and
logic means for controllably receiving said numeric time signal and producing a velocity signal in response to receiving said status signal, said velocity signal having a value responsive to said time signal.
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Accused Products
Abstract
Automatic guided vehicles require an accurate method and apparatus for determining vehicle velocity. The subject apparatus is associated with a vehicle having at least one surface engaging idler wheel. A resolver produces a rotation angle rate signal having a value responsive to the angular rotation rate of the idler wheel. A resolver-to-digital converter receives the rotation rate angle signal and produces a rotation rate pulse signal. A clock substantially continuously produces clock pulse signals having a predetermined frequency. A counter receives the rotation rate pulse signal and the clock pulse signal and controllably produces a time signal corresponding to the number of clock pulses received over the duration of a predetermined portion of the rotation rate pulse signal. A logic device controllably receives the time signal and produces a vehicle velocity signal.
23 Citations
3 Claims
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1. A velocity determining apparatus for a vehicle, said vehicle having at least one surface engaging wheel, comprising:
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resolver means for producing a rotation angle rate signal having a value responsive to the angular rotation rate of said wheel, said resolver means having a shaft rotatably connected to said wheel; converter means for receiving said rotation angle rate signal and producing a rotation rate pulse signal having a pulse duration responsive to said rotation angle rate signal; clock means for substantially continuously producing a clock pulse signal having a predetermined frequency; counter means for receiving said rotation rate pulse signal and said clock pulse signal and controllably producing a numeric time signal corresponding to the number of clock pulses received from said clock means over the duration of a predetermined portion of said rotation rate pulse signal and a status signal in response to termination of said predetermined portion of said rotation rate pulse signal; and logic means for controllably receiving said numeric time signal and producing a velocity signal in response to receiving said status signal, said velocity signal having a value responsive to said time signal. - View Dependent Claims (2, 3)
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Specification