Tilt and/or acceleration sensing apparatus and method
First Claim
1. A tilt sensing apparatus for a lawnmower, comprising:
- an accelerometer mounted to the lawnmower having a first sensing axis and a second sensing axis oriented at an angle with respect to the first sensing axis, wherein the accelerometer is configured to;
sense a first tilt angle defined between the first sensing axis and a horizontal reference plane and generate a corresponding first tilt signal;
sense a second tilt angle defined between the second sensing axis and the horizontal reference plane and generate a corresponding second tilt signal; and
a processor in operative communication with the accelerometer, configured to;
determine a maximum fall angle of the lawnmower based on the first tilt signal and the second tilt signal, wherein the maximum fall angle is an angle formed between a plane of the accelerometer and the horizontal reference plane;
compare the maximum fall angle to a first predetermined value; and
generate a first output signal when the maximum fall angle exceeds the first predetermined value.
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Accused Products
Abstract
A tilt or acceleration sensing apparatus and method that allows a tilt or acceleration sensing device of a vehicle to determine: 1) a maximum fall angle of the vehicle, regardless of the orientation of the vehicle and the vehicle'"'"'s tilt sensor(s) to the incline; or 2) the downward acceleration of the vehicle. In one embodiment, a method of determining a maximum fall angle of a vehicle includes sensing tilt angles of two sensing axes of the vehicle relative to a horizontal reference plane and calculating the maximum fall angle of the vehicle based on the tilt angles. The apparatus and method may also include comparing the maximum fall angle to predetermined values and generating output signals when the maximum fall angle exceeds the predetermined values. In another embodiment, a method of determining when a vehicle is sliding downhill includes sensing the accelerations of three sensing axes.
30 Citations
27 Claims
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1. A tilt sensing apparatus for a lawnmower, comprising:
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an accelerometer mounted to the lawnmower having a first sensing axis and a second sensing axis oriented at an angle with respect to the first sensing axis, wherein the accelerometer is configured to; sense a first tilt angle defined between the first sensing axis and a horizontal reference plane and generate a corresponding first tilt signal; sense a second tilt angle defined between the second sensing axis and the horizontal reference plane and generate a corresponding second tilt signal; and a processor in operative communication with the accelerometer, configured to; determine a maximum fall angle of the lawnmower based on the first tilt signal and the second tilt signal, wherein the maximum fall angle is an angle formed between a plane of the accelerometer and the horizontal reference plane; compare the maximum fall angle to a first predetermined value; and generate a first output signal when the maximum fall angle exceeds the first predetermined value. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A tilt sensing apparatus for a vehicle, comprising:
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an accelerometer for sensing at least first and second tilt angles relative to a horizontal reference plane and generating corresponding first and second tilt signals; a processor in operative communication with the accelerometer, a temperature sensor that generates a corresponding temperature signal in operative communication with the processor, said processor configured to; determine a maximum fall angle of the accelerometer based on the first tilt signal, the second tilt signal, and the temperature signal from the temperature sensor wherein the maximum fall angle is an angle formed between a plane of the accelerometer and the horizontal reference plane; compare the maximum fall angle to a first predetermined value; and generate a first output signal when the maximum fall angle exceeds the first predetermined value. - View Dependent Claims (8)
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9. A method of determining that a vehicle is accelerating down a slope, comprising:
- sensing an acceleration in a direction of a first sensing axis of the vehicle;
sensing an acceleration in a direction of a second sensing axis of the vehicle, wherein the second sensing axis is offset from the first sensing axis; sensing an acceleration in a direction of a third sensing axis of the vehicle, wherein the third sensing axis is offset from the first and second sensing axes; determining a magnitude of the vector sum of the accelerations sensed in the directions of the first, second, and third sensing axes; comparing the magnitude to a first predetermined value to determine whether the vehicle is accelerating down the slope; and generating a first output signal when the vehicle is accelerating down the slope. - View Dependent Claims (10, 11, 12)
- sensing an acceleration in a direction of a first sensing axis of the vehicle;
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13. An apparatus for determining that a vehicle is accelerating down a slope, comprising:
- a acceleration sensing device including;
a first sensing axis; a second sensing axis, wherein the second sensing axis is offset from the first sensing axis; and a third sensing axis, wherein the third sensing axis is offset from the first and second sensing axes; wherein the acceleration sensing device is configured to; sense an acceleration in a direction of the first sensing axis and generate a corresponding first acceleration signal; sense an acceleration in a direction of the second sensing axis and generate a corresponding second acceleration signal; and sense an acceleration in a direction of the third sensing axis and generate a corresponding third acceleration signal; and a processor in operative communication with the acceleration sensing device, configured to; determine a magnitude of the vector sum of the accelerations sensed in the directions of the first, second, and third sensing axes; compare the magnitude to a first predetermined value to determine whether the vehicle is accelerating down the slope; and generate a first output signal when the vehicle is accelerating down the slope. - View Dependent Claims (14, 15, 16, 17, 18)
- a acceleration sensing device including;
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19. An apparatus for determining that a vehicle is accelerating down a slope, comprising:
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means for sensing an acceleration in the direction of first, second, and third sensing axes and generating corresponding first, second, and third acceleration signals; a processor in operative communication with the means for sensing the accelerations, configured to; determine a magnitude of the vector sum of the accelerations sensed in the directions of the first, second, and third sensing axes; compare the magnitude to a first predetermined value to determine whether the vehicle is accelerating down the slope; and generate a first output signal when the vehicle is accelerating down the slope. - View Dependent Claims (20, 21, 22)
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23. A lawnmower including:
- a frame;
an engine supported by the frame;a mower deck having a cutting blade that is driven by the engine; at least one drive wheel that is driven by the engine; and an acceleration sensing apparatus supported by the frame for determining when the lawnmower is accelerating down a slope, wherein the acceleration sensing apparatus is configured to generate a first output signal when the lawnmower is accelerating down the slope. - View Dependent Claims (24, 25, 26, 27)
- a frame;
Specification