FORCE MOMENT SENSOR
First Claim
1. A force moment sensor for sensing forces and moments that are transferred from an input member to an output member, the force moment sensor comprising:
- a housing having a base portion and outer tube portion extending from the base portion and one of the input member and the output member is attachable to the base portion;
an inner tube operably connected to the base portion of the housing, spaced inwardly of the outer tube, the inner tube being a poled piezoceramic element;
a load plate attached to the inner tube, spaced from the base portion of the housing and spaced from the outer tube and having a circumference and a centre axis, the other of the input member and the output member is attachable to the load plate;
a plurality of elongate connectors connected between the load plate and the outer tube portion around the circumference of the load plate, each elongate connector defining a longitudinal axis and the longitudinal axes of the plurality of the elongate connectors intersect the centre axis of the load plate when an undeflected configuration; and
a plurality of dynamic deflection measuring devices attached to the load plate for measuring dynamic flexible deflections of the load plate.
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Accused Products
Abstract
A force moment sensor for sensing forces and moments in a system through which forces and moments are transferred from an input member to an output member is disclosed. It includes a housing, an inner tube, a load plate, a plurality of elongate connectors and a plurality of dynamic deflection measuring devices. The housing has a base portion and an outer tube portion generally orthogonal to the base portion. The inner tube, a poled piezoceramic element, is operably connected to the base portion and spaced inwardly of the outer tube. The load plate is attached to the inner tube, spaced from the base portion and spaced from the outer tube. The plurality of elongate connectors are connected between the load plate and the outer tube portion. The plurality of dynamic deflection measuring devices are attached to the load plate for measuring dynamic flexible deflections of the load plate.
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Citations
16 Claims
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1. A force moment sensor for sensing forces and moments that are transferred from an input member to an output member, the force moment sensor comprising:
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a housing having a base portion and outer tube portion extending from the base portion and one of the input member and the output member is attachable to the base portion; an inner tube operably connected to the base portion of the housing, spaced inwardly of the outer tube, the inner tube being a poled piezoceramic element; a load plate attached to the inner tube, spaced from the base portion of the housing and spaced from the outer tube and having a circumference and a centre axis, the other of the input member and the output member is attachable to the load plate; a plurality of elongate connectors connected between the load plate and the outer tube portion around the circumference of the load plate, each elongate connector defining a longitudinal axis and the longitudinal axes of the plurality of the elongate connectors intersect the centre axis of the load plate when an undeflected configuration; and a plurality of dynamic deflection measuring devices attached to the load plate for measuring dynamic flexible deflections of the load plate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A computer implemented method of determining a force and moment of an external load applied to a force moment sensor having an inner tube and a load plate, the method comprising the steps of:
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applying a current to the inner tube through a definable range of frequencies; extracting a resonant frequency and associated dynamic shape of the load plate over the range of frequencies; comparing the extracted resonant frequency and associated dynamic shape to a plurality of calibration shapes; and determining the external load. - View Dependent Claims (14, 15)
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16. A system for sensing forces and moments comprising:
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an input member; an output member; a force moment sensor having a housing, an inner tube including a poled piezoceramic element, a load plate attached to the inner tube and spaced from the housing and a plurality of elongate connectors connected between the load plate and the housing and a plurality of dynamic deflection measuring devices and the housing being connected to one of the input member and the output member and the load plate being connected to the other of the input member and the output member; a processing means for determining the external load applied to the force moment sensor.
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Specification