Systems and methods for low latency 3-axis accelerometer calibration
First Claim
1. A telematics system, comprising:
- a processor;
a global positioning system (GPS) receiver coupled to the processor and configured to determine a vehicle'"'"'s information;
an acceleration sensor connected to the processor and configured to determine acceleration information samples comprising forward acceleration information along a forward axis, lateral acceleration information along a lateral axis, and vertical acceleration information along a vertical axis, wherein the forward axis, lateral axis, and vertical axis of the acceleration sensor are misaligned from a vehicular forward axis, a vehicular lateral axis, and a vehicular vertical axis;
a velocity sensor connected to the processor and configured to determine heading information and velocity information along the vehicular forward axis; and
a memory connected to the processor and storing an acceleration alignment application;
wherein the processor, on reading the acceleration alignment application, is directed to;
obtain at least one velocity information sample using the velocity sensor;
obtain at least one acceleration information sample using the acceleration sensor;
calculate a lateral incline vector by computing the cross product of the velocity information along the vehicular forward axis described in the at least one velocity information sample and a calibrated forward vector;
calculate a lateral acceleration vector based on the lateral incline vector and the calibrated forward vector;
calculate a forward incline vector by computing the cross product of the lateral incline vector and the lateral acceleration information described in the acceleration information sample;
calculate a forward acceleration vector using the forward incline vector and the lateral acceleration vector;
map the forward axis of the acceleration sensor to the vehicular forward axis based on the lateral incline vector and the lateral acceleration vector, thereby calibrating the orientation of the accelerometer so that the forward axis of the acceleration sensor corresponds to the vehicular forward axis; and
report the vehicle'"'"'s status including location, heading, velocity, and acceleration using the calibrated data from the acceleration sensor to correct for GPS receiver errors.
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Abstract
Systems and methods for low-latency calibration of the alignment of 3-axis accelerometers in accordance embodiments of the invention are disclosed. In one embodiment of the invention, a telematics system includes a processor, an acceleration sensor, a velocity sensor, and a memory configured to store an acceleration alignment application, wherein the acceleration alignment application configures the processor to determine vehicular forward acceleration information and vehicular lateral acceleration information, calculate a lateral acceleration vector, a forward acceleration vector, and a vertical acceleration vector using a forward incline vector and a lateral incline vector determined using the vehicular forward acceleration information and vehicular lateral acceleration information.
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Citations
16 Claims
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1. A telematics system, comprising:
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a processor; a global positioning system (GPS) receiver coupled to the processor and configured to determine a vehicle'"'"'s information; an acceleration sensor connected to the processor and configured to determine acceleration information samples comprising forward acceleration information along a forward axis, lateral acceleration information along a lateral axis, and vertical acceleration information along a vertical axis, wherein the forward axis, lateral axis, and vertical axis of the acceleration sensor are misaligned from a vehicular forward axis, a vehicular lateral axis, and a vehicular vertical axis; a velocity sensor connected to the processor and configured to determine heading information and velocity information along the vehicular forward axis; and a memory connected to the processor and storing an acceleration alignment application; wherein the processor, on reading the acceleration alignment application, is directed to; obtain at least one velocity information sample using the velocity sensor; obtain at least one acceleration information sample using the acceleration sensor; calculate a lateral incline vector by computing the cross product of the velocity information along the vehicular forward axis described in the at least one velocity information sample and a calibrated forward vector; calculate a lateral acceleration vector based on the lateral incline vector and the calibrated forward vector; calculate a forward incline vector by computing the cross product of the lateral incline vector and the lateral acceleration information described in the acceleration information sample; calculate a forward acceleration vector using the forward incline vector and the lateral acceleration vector; map the forward axis of the acceleration sensor to the vehicular forward axis based on the lateral incline vector and the lateral acceleration vector, thereby calibrating the orientation of the accelerometer so that the forward axis of the acceleration sensor corresponds to the vehicular forward axis; and report the vehicle'"'"'s status including location, heading, velocity, and acceleration using the calibrated data from the acceleration sensor to correct for GPS receiver errors. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for a telematics system, wherein the telematics system comprises an acceleration sensor, a processor, a global positioning system (GPS) receiver and a memory and the telematics system is mounted in a vehicle, wherein a forward axis, a lateral axis, and a vertical axis of the acceleration sensor is respectively misaligned from a vehicular forward axis, a vehicular lateral axis, and a vehicular vertical axis, the method comprising:
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obtaining at least one velocity information sample using the telematics system; obtaining at least one acceleration information sample using the telematics system; calculating a lateral incline vector by computing the cross product of velocity information along the vehicular forward axis described in the at least one velocity information sample and a calibrated forward vector using the telematics system; calculating a lateral acceleration vector based on the lateral incline vector and the calibrated forward vector using the telematics system; calculating a forward incline vector by computing the cross product of the lateral incline vector and the lateral acceleration information described in the acceleration information sample using the telematics system; calculating a forward acceleration vector using the forward incline vector and the lateral acceleration vector using the telematics system; mapping the forward axis of the acceleration sensor to the vehicular forward axis based on the lateral incline vector and the lateral acceleration vector, thereby calibrating the orientation of the accelerometer so that the forward axis of the acceleration sensor corresponds to the vehicular forward axis using the telematics system; and reporting the vehicle'"'"'s status including location, heading, velocity, and acceleration using the calibrated data from the acceleration sensor to correct for GPS receiver errors. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification