Patent ID: 7280935
Filing Date: 2007-10-09
Classification: G01D

Abstract:
1. A system comprising: a first sensor assembly including a first sensor element attached to a first sensor arm, a second sensor element attached to a movable element, and a first actuator that adjusts the first sensor arm, wherein the first sensor assembly generates first positional signals indicative of a first distance between the first and second sensor elements; a second sensor assembly including a third sensor element attached to a second sensor arm, a fourth sensor element attached to the movable element, and a second actuator that adjusts the second sensor arm, wherein the second sensor assembly generates second positional signals indicative of a second distance between the third and fourth sensor elements; and a sensor assembly controller coupled to the first and second sensor assemblies that receives the first and second positional signals and identifies a position of the movable element based on at least one of the first and second positional signals, wherein the sensor assembly controller causes the first and second sensor arms to adjust in a leapfrogging fashion to ensure that at least one of the first and second sensor assemblies is always within its respective operational range as the movable element moves, wherein the sensor assembly controller causes the first actuator to adjust the first sensor arm when the first positional signals indicate that the first sensor assembly is out of range, and re-calibrates the first sensor assembly following adjustment of the first sensor arm based on the position of the movable element as determined by the second positional signals, and wherein the sensor assembly controller associates the first distance following adjustment of the first sensor arm with the position of the movable element as determined by the second distance to re-calibrate the first sensor assembly.