Patent ID: 8531182

Claim:
A control system comprising: a control input device having a pivotally movable magnet relative to two perpendicular axes (X) and (Y); a pole-piece frame arrangement positioned about the magnet for influencing the flux lines thereof, three magnetic flux sensors being positioned in said pole-piece frame arrangement for sensing movement of the magnet, said three magnetic flux sensors being substantially equally spaced 120° apart around said magnet, one of said magnetic flux sensors positioned on a first one of said axes (X) such that an output signal (A) thereof is representative of the position of said control input device relative to said first axis, a monitoring arrangement for monitoring the output signal of each of said three sensors and further effective to calculate the position of the control input device relative to the second axis (Y) by: Y = 1 3 × ( B - C ) wherein (B) and (C) respectively are the output signals of said other two magnetic flux sensors, not positioned on said first axis, generate a check value by summing the output signals of all of said three magnetic flux sensors, or the representative signals thereof, and generate a signal effective to implement a fail-safe process when said check value exceeds a predetermined threshold value.