De-centralized control architecture for improved sensitivity of accelerometer-based gravity gradiometers

摘要

A method for rebalancing a group of accelerometers in a gravity gradiometer instrument (GGI) includes the steps of defining and implementing a number of group-wise actuation constrainment modes based on a design of the gravity gradiometer instrument and its accelerometers. Implementing one constrainment mode comprises differentially scaling and distributing a single electrical current to multiple accelerometers' rebalance circuitry to cancel a specific acceleration effect experienced by the group of accelerometers or gradiometer as a whole. Superposition of a number of such modes enables rebalancing the full acceleration environment experienced by the group of accelerometers, given negligible local differential acceleration effects specific to, say, an individual accelerometer of the assembly. Mathematically, the multiple of constrainment modes are encapsulated by an actuation or constrainment modal influence matrix, arranged one mode per column of the matrix, and the electrical currents of respective modes are encapsulated in a vector listing of currents.

主权项

1. A method of rebalancing a plurality of accelerometers arranged in a gravity gradiometer instrument (GGI), each accelerometer of said plurality of accelerometers being decoupled from each other accelerometer, the method comprising the steps of:
implementing at least one constrainment mode, wherein each of said at least one constrainment mode corresponds to a subset of accelerometers in said plurality of accelerometers; defining an actuation modes matrix, each column of said actuation modes matrix containing a vector listing of summation coefficients for accelerometers of a constrainment mode associated with the column of the actuation modes matrix; generating a vector listing of constrainment currents for each accelerometer associated with said at least one constrainment mode and applying said vector listing of constrainment currents to said actuation modes matrix to generate an actuation current for each at least one constrainment mode; applying said generated actuation current to each accelerometer associated with said at least one constrainment mode.