Method of and apparatus for the elimination of the effects of inertial interference in force measurement systems, including touch-input computer and related displays employing touch force location measurement techniques
First Claim
1. A method of measuring force and/or torque to be applied to a mechanically movable or disturbable system, including, where desired, objects associated therewith and portions of force measuring apparatus itself, that comprises, sensing one or more components of force and/or torque applied to the system by deliberate forces acting thereupon to provide force and/or torque measurements uncorrected by inertial interference motion effects that arise;
- deriving time derivatives including at least a set of the second order derivatives of the uncorrected force measurements and subtracting the same in different combinations of each order in turn from each channel of uncorrected force measurement, with coefficients of combination chosen such that the resulting sums reflect tie desired force measurements substantially free of inertial motion interference errors.
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Accused Products
Abstract
A method and apparatus is disclosed, particularly, though by no means exclusively, useful in touch—screen computer CRT display systems and the like, and more generally in other force and/or torque measurement systems, as in weighing and the like, in which (1) lineal and/or rotational acceleration of the system is sensed in response to inertial interference effects such as tilt or movement that introduce errors into the force and/or torque measurements, and/or (2) inertial error correction from the force data itself is obtained, such as derivative order corrections; and such data is used to correct the force and/or torque measurements. A novel calibration technique for deriving appropriately descriptive coefficients to the particular system for the correcting data, is also disclosed.
105 Citations
8 Claims
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1. A method of measuring force and/or torque to be applied to a mechanically movable or disturbable system, including, where desired, objects associated therewith and portions of force measuring apparatus itself, that comprises, sensing one or more components of force and/or torque applied to the system by deliberate forces acting thereupon to provide force and/or torque measurements uncorrected by inertial interference motion effects that arise;
- deriving time derivatives including at least a set of the second order derivatives of the uncorrected force measurements and subtracting the same in different combinations of each order in turn from each channel of uncorrected force measurement, with coefficients of combination chosen such that the resulting sums reflect tie desired force measurements substantially free of inertial motion interference errors.
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2. A method of measuring force and/or torque to be applied to a mechanically movable or disturbable system, including, where desired, objects associated therewith and portions of force measuring apparatus itself, that comprises, sensing one or more components of force and/or torque applied to the system by deliberate forces acting thereupon to provide force and/or torque measurements uncorrected by inertial interference motion effects that arise;
- intentionally moving and disturbing the system in various ways while the said deliberate forces ultimately to be measured are not applied and are allowed to remain at zero, in order to generate measurements that enable calibration of the system that renders the same less prone to force measurement errors due to motions of the type created by said moving and disturbing.
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3. Apparatus for measuring force and/or torque to be applied to a mechanically movable or disturbable system, including, where desired, objects associated therewith and portions of force measuring apparatus itself, having, in combination, means for sensing one or more components of force and/or torque applied to the system by forces acting thereupon to provide force and/or torque measurements uncorrected for inertial interference motion effects that arise;
- means for sensing lineal and/or rotational acceleration of the system in response to such inertial interference motions; and
means for correcting the uncorrected force and/or torque measurements in response to the acceleration sensing to achieve elimination from the measurements of the effects of such inertial interference. - View Dependent Claims (4, 5, 6, 7, 8)
- means for sensing lineal and/or rotational acceleration of the system in response to such inertial interference motions; and
Specification