Hall-effect-based angular orientation sensor and corresponding method

Method for sensing an angular orientation of a projection of a magnetic field vector of a magnetic field into a plane, said method comprising the steps of

• a) providing at least a first set of N≧2 Hall effect devices, each having a detection direction and comprising two pairs of connectors, wherein, in presence of said magnetic field, a flow of an electric current between the connectors of any of said pairs of connectors allows to pick up a Hall voltage between the connectors of the other respective pair of connectors induced by said magnetic field, unless a magnetic field component of said magnetic field along said detection direction is zero, wherein said N Hall effect devices are aligned such that their detection directions lie in said plane, and wherein at least two of said Hall effect devices have non-identical detection directions;
• b) providing at least one filtering-or-resonating unit comprising an input and structured and configured for altering an inputted signal of a fundamental frequency f=1/Tf, said inputted signal containing, in addition to said fundamental frequency, higher harmonics, in such a way that an intensity of said higher harmonics is decreased relative to an intensity of said fundamental frequency;
• c) providing at least one current source comprising an output and capable of outputting an electrical current at its output;
• wherein a particular way of wiring both pairs of connectors of a Hall effect device to said output of said current source or to said input of said filtering-or-resonating unit is referred to as a “wiring scheme”, wherein two wiring schemes are referred to as “orthogonal” wiring schemes if a pair of connectors connected to the current source in one of the two wiring schemes is connected to said filtering-or-resonating unit in the other of the two wiring schemes, and wherein two wiring schemes are referred to as “reverse” wiring schemes if they lead to different signs of the Hall voltage;
• d1) applying, during a first time period of a duration 0.5 Tf and in a specific sequence of said N Hall effect devices, to each of said N Hall effect devices a respective wiring scheme Wi+, i=1, . . . ,N, during respective subsequent time periods of durations ti, i=1, . . . ,N;
• and
• d2) applying, during a second time period of a duration 0.5 Tf, subsequent to said first time period of a duration 0.5 Tf, and in the same specific sequence of said N Hall effect devices, to each of said N Hall effect devices a respective wiring scheme Wi−, i=1, . . . ,N, during respective subsequent time periods of the same durations ti, i=1, . . . ,N;
• wherein each of said wiring schemes Wi+ is an orthogonal and reverse wiring scheme of the respective other wiring scheme Wi−, i=1, . . . ,N;
• and
• e) deriving from signals outputted by said filtering-or-resonating unit in reaction to carrying out steps d1) and d2) an output signal indicative of said angular orientation.

Sensor for sensing an angular orientation of a projection of a magnetic field vector of a magnetic field into a plane, said sensor comprising

• at least a first and a second Hall effect devices each having a detection direction, said detection directions of said first and a second Hall effect devices being aligned with respect to each other in a non-parallel fashion, said Hall effect devices each comprising two pairs of connectors, wherein, in presence of said magnetic field, a flow of an electric current between the connectors of any of said pairs of connectors allows to pick up a Hall voltage between the connectors of the other respective pair of connectors induced by said magnetic field unless a magnetic field component of said magnetic field along said detection direction is zero;
• at least one filtering-or-resonating unit comprising an input and an output;
• at least one current source comprising an output for outputting an electrical current at its output;
• a wiring unit operationally connected to each of said connectors of each of said Hall effect devices structured and configured for selectively wiring said pairs of connectors to said output of said current source or to said input of said filtering-or-resonating unit, wherein a particular way of wiring both pairs of connectors of a Hall effect device is referred to as a “wiring scheme”, wherein two wiring schemes are referred to as “orthogonal” wiring schemes if a pair of connectors connected to the current source in one of the two wiring schemes is connected to said filtering-or-resonating unit in the other of the two wiring schemes, and wherein two wiring schemes are referred to as “reverse” wiring schemes if they lead to different signs of the Hall voltage;
• a control unit structured and configured for controlling said wiring unit in such a way that
• for a duration of a duration Tf/4 a first wiring scheme is applied to said at least one first Hall effect device, and subsequently,
• for a duration of a duration Tf/4, a second wiring scheme is applied to said second Hall effect device, and subsequently,
• for a duration of a duration Tf/4, a third wiring scheme is applied to said first Hall effect device, and subsequently,
• for a duration of a duration Tf/4, a fourth wiring scheme is applied to said second Hall effect device;
• wherein said first and third wiring schemes are orthogonal and reverse wiring schemes;
• and
• wherein said second and fourth wiring schemes are orthogonal and reverse wiring schemes;
• an output unit operationally connected to said output of said filtering-or-resonating unit structured and configured for obtaining from a signal outputted from said filtering-or-resonating unit an output signal indicative of said angular orientation and for outputting said signal;
• wherein said filtering-or-resonating unit is structured and configured for filtering an inputted signal of a fundamental frequency f=1/Tf containing, in addition to said fundamental frequency, higher harmonics in such a way that an intensity of said higher harmonics is decreased relative to an intensity of said fundamental frequency.