Inclinometer
AssigneeInterlink Electronics, Inc.
InventorStuart I. Yaniger
Life of this patent
Estimating the term…
Abstract
A two-axis tilt sensor, or inclinometer (10), uses a spherical reference element (18) floating in an inert fluid (20) and including a magnet (42) to produce an asymmetrical weight distribution. The asymmetrical weight distribution maintains the spherical reference element at a constant orientation with respect to gravity, while the position of the magnet on the spherical reference element with respect to a housing (12) is detected by opposing pairs of Hall effect sensors (22) mounted on the housing. The outputs from opposing pairs of sensors are processed by differential amplifier circuits (80) to determine signals corresponding to the tilt of the inclinometer about the axes.
Claims10
An apparatus for sensing tilt, comprising:
- a housing having walls that define a cavity;
- a generally spherical reference element rotatably positioned within the cavity;
- a single magnet positioned within the spherical reference element imparting an asymmetrical weight distribution and a predetermined magnetic field orientation thereto;
- a fluid supporting the reference element within the cavity;
- a first pair of Hall effect sensors positioned within the housing on opposite sides of the reference element for generating a first pair of electrical signals in response to the orientation of the magnetic field relative to a first axis of the housing;
- a second pair of Hall effect sensors positioned within the housing on opposite sides of the reference element for generating a second pair of electrical signals in response to the orientation of the magnetic field relative to a second axis of the housing;
- and
- first and second balanced differential amplifiers electrically connected to the respective first and second pairs of electrical signals to produce first and second inclination angle signals related to a tilt of the respective first and second axes of the housing relative to the orientation of the magnetic field.
A method for sensing tilt, comprising:
- positioning a single magnet within a spherical reference element to impart an asymmetrical weight distribution and a predetermined magnetic field orientation thereto;
- providing a housing with a cavity therein;
- placing the reference element within the cavity;
- filling the cavity with a fluid to support the reference element such that it freely rotates within the cavity;
- positioning a first pair of Hall effect sensors within the housing on opposite sides of the reference element for generating a first pair of electrical signals in response to the orientation of the magnetic field relative to a first axis of the housing;
- positioning a second pair of Hall effect sensors within the housing on opposite sides of the reference element for generating a second pair of electrical signals in response to the orientation of the magnetic field relative to a second axis of the housing;
- and
- generating first and second inclination angle signals related to a tilt of the respective first and second axes of the housing relative to the orientation of the magnetic field by differentially amplifying the respective first and second pairs of electrical signals.
Dependencies are inferred from the claim text.