Apparatus and method for sensing motionlessness in a vehicle
First Claim
1. A method for sensing motionlessness in a land-based vehicle having inertial sensors, each of said sensors providing motion signals, comprising the steps of:
- (a) sensing a reference sample representative of said motion signals during a reference period;
(b) extracting a reference characteristic signal from said reference sample, said reference characteristic signal further being representative of motionlessness;
(c) sensing an operational sample representative of said motion signals during an operational period;
(d) extracting an operational characteristic signal from said operational sample, said operational characteristic signal further being representative of a current motion state;
(e) determining said current motion state from said operational characteristic signal relative to said reference characteristic signal, said motion state being one of stopped and moving, said stopped state being indicative of motionlessness;
(f) reporting said motion state to a target application in said vehicle, said target application acting in accordance therewith;
(g) if said motion state is moving, then repeating steps (c) through (h);
(h) if said motion state is stopped, then recalibrating said inertial sensors, and repeating steps (c) through (h); and
wherein said reference characteristic signal includes a first standard deviation representative of said reference sample, and said operational characteristic signal includes a second standard deviation representative of said operational sample.
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Accused Products
Abstract
An apparatus and method for sensing motionlessness for sensing motionlessness in a land-based vehicle is provided. The apparatus can include an inertial measurement unit (IMU) mounted in a predetermined orientation on the vehicle and a programmable computer. The IMU can have an inertial sensor which generates a plurality of motion signals. More than one inertial sensor can be used and, in that case, each of the sensors can be mounted in a second predetermined orientation with respect to the others, such as an orthogonal orientation, thereby creating a selected spatial reference frame. The inertial sensor can be one or more accelerometers, or one or more gyroscopes, or an accelerometer-gyroscope combination. The computer receives the motion signals and determining a motion state of the vehicle therefrom. The computer provides the motion state to a target application which acts in accordance therewith. The method can include sensing a reference sample of motion signals during a reference period; extracting a reference characteristic signal from the reference sample; sensing an operational sample during an operational period; extracting an operational characteristic signal from the operational sample; determining the current motion state by comparing the operational characteristic signal to the reference characteristic signal; reporting the motion state to a target application in the vehicle, the application acting in accordance therewith.
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Citations
12 Claims
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1. A method for sensing motionlessness in a land-based vehicle having inertial sensors, each of said sensors providing motion signals, comprising the steps of:
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(a) sensing a reference sample representative of said motion signals during a reference period; (b) extracting a reference characteristic signal from said reference sample, said reference characteristic signal further being representative of motionlessness; (c) sensing an operational sample representative of said motion signals during an operational period; (d) extracting an operational characteristic signal from said operational sample, said operational characteristic signal further being representative of a current motion state; (e) determining said current motion state from said operational characteristic signal relative to said reference characteristic signal, said motion state being one of stopped and moving, said stopped state being indicative of motionlessness; (f) reporting said motion state to a target application in said vehicle, said target application acting in accordance therewith; (g) if said motion state is moving, then repeating steps (c) through (h); (h) if said motion state is stopped, then recalibrating said inertial sensors, and repeating steps (c) through (h); and wherein said reference characteristic signal includes a first standard deviation representative of said reference sample, and said operational characteristic signal includes a second standard deviation representative of said operational sample. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for sensing motionlessness in a land-based vehicle having inertial sensors, each of said sensors providing motion signals, comprising the steps of:
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(a) sensing a reference sample representative of said motion signals during a reference period; (b) extracting a reference characteristic signal from said reference sample, said reference characteristic signal further being representative of motionlessness; sensing an operational sample representative of said motion signals during an operational period; (d) extracting an operational characteristic signal from said operational sample, said operational characteristic signal further being representative of a current motion state; (e) determining said current motion state from said operational characteristic signal relative to said reference characteristic signal, said motion state being one of stopped and moving, said stopped state being indicative of motionlessness; (f) reporting said motion state to a target application in said vehicle, said target application acting in accordance therewith; (g) if said motion state is moving, then repeating steps (c) through (h); (h) if said motion state is stopped, then recalibrating said inertial sensors, and repeating steps (c) through (h); wherein each of said inertial sensors are mounted in a predetermined orientation respective of others of said inertial sensors, said orientation providing a selected spatial reference frame thereby; and wherein step (h) further comprises at least one of realigning said selected spatial reference frame and selectively revising said reference characteristic signal.
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Specification