Digital rotation detecting apparatus
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorJyoji Kawai
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Abstract
A digital rotation detecting apparatus of the invention, which is adapted to detect a phase angle .theta..sub.r of a resolver by using a multiple frequency clock of the excitation frequency for the resolver and a clock of a voltage control oscillator, is detectable of an instantaneous value of the phase angle .theta..sub.r at a desired time without delay, is also detectable directly of the rotational speed, and requires no low frequency excitation because the excitation frequency for the resolver needs only to be constant.
Claims6
A digital rotation detecting apparatus which excites a two-phase resolver by an exciter so as to synchronize phases of an output of said two-phase resolver and a predetermined signal, thereby detecting a rotation angle of said two-phase resolver, comprising:
- a two-phase signal generator;
- a phase difference detector which constitutes a phase locked loop together with said two-phase signal generator so as to detect a phase difference between the output of said two-phase resolver and that of said two-phase signal generator;
- a voltage control oscillator which constitutes said phase locked loop and outputs a frequency signal determined by the output of said phase-difference detector;
- and
- a first counting means which makes one of the output frequency of said voltage control oscillator and a frequency relating to the frequency of the output of said exciter an object of up count, and makes the other an object of down count, thereby detecting the rotation angle of said two-phase resolver.
A digital rotation detecting apparatus which excites a two-phase resolver by an exciter so as to synchronize phases of an output of said two-phase resolver and a predetermined signal, thereby detecting a rotation angle of said two-phase resolver, comprising:
- a two-phase signal generator;
- a phase difference detector which constitutes a phase locked loop together with said two-phase signal generator so as to detect a phase difference between the output of said two-phase resolver and that of said two-phase signal generator;
- a voltage control oscillator which constitutes said phase locked loop and outputs a frequency signal determined by the output of said phase-difference detector;
- a first counting means which makes one of the output frequency of said voltage control oscillator and a frequency relating to the frequency of the output of said exciter an object of up count, and makes the other an object of down count, thereby detecting the rotation angle of said two-phase resolver;
- and
- a data latch circuit for latching the counted value by said first counting means;
- whereby the counted value by said first counting means is latched periodically by said data latch circuit and said first counting means is reset so as to detect the rotational speed as the value latched by said data latch circuit.
A digital rotation detecting apparatus which excites a two-phase resolver by an exciter to control the frequency of said exciter so as to synchronize phases of output of said two-phase resolver and output of a two-phase reference oscillator, thereby detecting a rotation angle of said two-phase resolver, comprising:
- a counting means which makes one of a frequency relating to the frequency of the output of said two-phase reference oscillator and a frequency relating to the frequency of the output of said exciter an object of up count, and makes the other an object of down count, thereby detecting the rotation angle of said two-phase resolver.
Dependencies are inferred from the claim text.