Patent ID: 8587775

Claim:
A positioning system to cause a solar array to face the sun, the system comprising: a mount that defines a first axis and a second axis angularly displaced from the first axis; a solar array connected to said mount such that said solar array is rotatable about said first and second axes, the second axis for pivoting the solar array in a vertical direction; at least one motor operatively connected through a coupling to the solar array to effect movement of the solar array about the first axis and the second axis, the at least one motor having a measurable rotational shaft position; a first sensor to output the at least one motor measured rotational shaft position; an ephemeris calculator configured to output an anticipated orientation of the sun relative to a known geographic location of the solar array; a command calculator configured to generate at least one motor shaft rotational position command in response to the anticipated sun orientation; at least one motor control loop responsive to a difference between the at least one motor shaft rotational position command and the at least one motor measured rotational shaft position, and which outputs at least one a motor drive signal to which the at least one first motor is responsive, such that the difference is made to approach zero; an elevation drive assembly driven by the at least one motor, the elevation drive assembly configured to pivot the solar array about the second axis; a physical stop positioned on the elevation drive assembly and configured to halt elevation of the solar array about the second axis, whereby a location of the stop on the elevation drive assembly is fed into the command calculator such that a number of Hall counts is initialized to zero by the command calculator at the location of the stop; and wherein the solar array is positioned to face the sun as the sun moves with respect to the array geographic location and outputs solar electric energy.