Grade angle and acceleration sensor
First Claim
1. A grade and acceleration sensor for measuring the angle of a road grade being traversed by a vehicle and the vehicle'"'"'s acceleration, said grade and acceleration sensor comprising:
- a weight having a predetermined mass m;
a first sensor for generating a first signal indicative of a first parameter caused by said weight in response to at least the force of gravity acting on said weight;
a second sensor for generating a second signal indicative of a second parameter caused by said weight in response to the combined forces of gravity and acceleration of said vehicle acting on said weight;
grade angle logic means responsive to said first and second signals for generating a grade angle signal having a value corresponding to the grade angle θ
of the grade being traversed by the vehicle; and
acceleration logic means responsive to said first and second signals for generating an acceleration signal having a value corresponding to the acceleration "a" of the vehicle.
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Accused Products
Abstract
A grade and acceleration sensor having a weight, a first sensor for measuring a first parameter of the weight due at least to the force of gravity to generate a first signal, a second sensor for measuring a second parameter of the weight due to both the force of gravity and the acceleration of the vehicle on which the sensor is mounted to generate a second signal, a grade angle generator generating the grade angle θ in response to the first and second signal, and an acceleration generation generating a signal having a value corresponding to the acceleration of the vehicle in response to the first and second signals. In a first embodiment, the weight is a bob of a pendulum, the first parameter is a displacement angle of the bob due to acceleration and gravity and the second parameter is the force on the arm of the bob due to gravity and acceleration. In a second embodiment, the first parameter is force generated by a weight due to gravity along a first axis and the second parameter is the force generated by the weight due to acceleration and gravity along a second axis normal to the first axis.
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Citations
25 Claims
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1. A grade and acceleration sensor for measuring the angle of a road grade being traversed by a vehicle and the vehicle'"'"'s acceleration, said grade and acceleration sensor comprising:
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a weight having a predetermined mass m; a first sensor for generating a first signal indicative of a first parameter caused by said weight in response to at least the force of gravity acting on said weight; a second sensor for generating a second signal indicative of a second parameter caused by said weight in response to the combined forces of gravity and acceleration of said vehicle acting on said weight; grade angle logic means responsive to said first and second signals for generating a grade angle signal having a value corresponding to the grade angle θ
of the grade being traversed by the vehicle; andacceleration logic means responsive to said first and second signals for generating an acceleration signal having a value corresponding to the acceleration "a" of the vehicle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
- 15. The sensor of claim 13 wherein said F3 generator generates said signal F3 in accordance with the equation
- space="preserve" listing-type="equation">F.sub.3 =mg sin θ
where m is the mass of said weight, and g is the force of gravity. - space="preserve" listing-type="equation">F.sub.3 =mg sin θ
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16. The sensor of claim 15 further comprising:
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first biasing means for biasing said weight toward said first sensor along said first axis; second biasing means for biasing said weight toward said second sensor along said second axis; means for subtracting from said first signal a force corresponding to the force generated by said first biasing means; and means for subtracting from said second signal a force corresponding to the force generated by said second biasing means.
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17. The sensor of claim 13 wherein said acceleration value generator generates two different values for the acceleration α
- , said sensor further comprises accel/decel logic means for selecting one of said two different values of said acceleration in response to previously generated grade angles θ and
the values of the previously generated acceleration.
- , said sensor further comprises accel/decel logic means for selecting one of said two different values of said acceleration in response to previously generated grade angles θ and
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18. The sensor of claim 13 wherein said grade angle generator may generate a grade angle θ
- having two different values, θ and
180°
-θ
, and said acceleration value generator may generate two different acceleration values, +a and -a, said sensor further comprising;an acceleration direction sensor generating a first signal in response to detecting when the vehicle is accelerating and a second signal in response to when the vehicle is decelerating; grade angle logic means responsive to said grade angles generated by said grade angle generator, said first signal and said second signal to select one of said two different values; and acceleration/deceleration logic responsive to the values of said acceleration values generated by said acceleration value generator, said first and said second signals to select one of said two different acceleration values.
- having two different values, θ and
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19. The sensor of claim 11 wherein said first and second force sensors each comprise:
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a piezoelectric crystal engaged by said weight, said piezoelectric crystal having electrical properties variable as a function of the force exerted by said weight; an oscillator circuit controlled by said piezoelectric crystal, the frequency of said oscillator variable as a function of the forces exerted by said weight on said piezoelectric crystal; and frequency-to-analog converter means for converting said frequency generated by said oscillator circuit to an analog signal having a value corresponding to the force applied by said weight to said piezoelectric crystal.
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20. The sensor of claim 11 wherein said grade angle generator generates two different values for the grade angle θ
- , said sensor further comprising grade angle logic means for selecting one of said two different grade angles in response to previously generated grade angles θ and
values of said acceleration α
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- , said sensor further comprising grade angle logic means for selecting one of said two different grade angles in response to previously generated grade angles θ and
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21. A method for generating a grade angle θ
- and an acceleration value a for a vehicle, comprising the steps of;
detecting a first parameter produced by a weight in response to at least the force of gravity acting on said weight to generate a first signal; detecting a second parameter produced by a weight in response to the combined forces of gravity and acceleration acting on said weight to generate a second signal; generating a grade angle signal θ
corresponding to the angle of a grade being traversed by said vehicle in response to said first and second signal; andgenerating an acceleration signal "a" corresponding to the acceleration of said vehicle in response to said first and second signals. - View Dependent Claims (22, 23, 24, 25)
- and an acceleration value a for a vehicle, comprising the steps of;
Specification