Digital circuitry and method for calculating inclinometer angles
AssigneeMurata Manufacturing Co., Ltd.
InventorsRauli Collin, Antti Finne
Life of this patent
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Abstract
A method is disclosed for performing calculations for an inclinometer device, as is a digital circuitry for performing such calculations. The circuitry comprises an interface for receiving detection signals from a sensor device and a CORDIC unit for performing calculation of inclinometer output values characterizing a resultant vector. The CORDIC calculation unit is configured to perform a calculation for resolving the angle between a resultant vector and a programmable reference value using hyperbolic CORDIC calculation. Pre-rotation may be performed for a vector before hyperbolic CORDIC arctangent calculation phases.
Claims18
A digital circuitry configured to perform calculations for an inclinometer device, the circuitry comprising:
- an interface configured to receive detection signals from a sensor device;
- and
- a CORDIC unit configured to perform calculations of inclinometer output values characterizing a resultant vector,
- wherein the CORDIC unit is configured to perform a first calculation for resolving an angle between a resultant vector representing the detection signals and a programmable reference value, the first calculation including at least two hyperbolic CORDIC calculation phases,
- wherein the first calculation comprises:
- determining a first intermediate result corresponding to a length of a projection of the resultant vector on a reference axis times a multiplier representing the change of the length of the vector by using a hyperbolic CORDIC arctangent function;
- determining a second intermediate result corresponding to a length of a component of the resultant vector orthogonal with a reference axis multiplied with a multiplier representing a change of the length of the vector using the hyperbolic CORDIC arctangent function;
- and
- determining an angle between the resultant vector and a calculated axis orthogonal to the reference axis based on the first and the second intermediate results using a circular CORDIC arctangent function.
A method for performing calculations for an inclinometer device, the method performed based on detection signals received from a sensor device and the method comprising calculations of inclinometer output values characterizing a resultant vector, wherein the calculations are performed by a CORDIC unit, the method comprising:
- performing a first calculation for resolving an angle between a resultant vector representing the detection signals and a programmable reference value, the first calculation including at least two hyperbolic CORDIC calculation phases,
- wherein performing first calculation comprises:
- determining a first intermediate result corresponding to a length of a projection of the vector on a reference axis times a multiplier representing the change of the length of the vector by using a hyperbolic CORDIC arctangent function;
- determining a second intermediate result corresponding to a length of the component of the vector orthogonal with the reference axis multiplied with the multiplier representing the change of the length of the vector using a hyperbolic CORDIC arctangent function;
- and
- determining an angle between the resultant vector and a calculated axis orthogonal to the reference axis based on the first and the second intermediate results using a circular CORDIC arctangent function.
Dependencies are inferred from the claim text.