Method for detection of the angular position of a part driven in rotation and instrumentation using it
AssigneeRegie Nationale des Usines Renault
InventorClaude Leichle
Life of this patent
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Abstract
A shaft, the angular position of which is to be detected, equipped with a notched disk one tooth of which has been removed. A position sensor detects the passage of the teeth for a Schmitt trigger with its output connected to the inputs of two monostable multivibrators, to the up-down counter input of a counter, to one input of an AND gate and to the inputs of logic circuits. The held output of the counter is connected to an input of a type D flip-flop connected at its output to the second input of the AND gate.
Claims9
A method of detecting the angular position of a part driven in rotation, integral with a disk provided on its periphery with a succession of mechanically identical teeth and notches and having one tooth removed to constitute an absolute reference, comprising the steps of:
- locating a position sensor next to the periphery of the disk to detect the passage of the teeth and notches;
- opertating a pulse generator at a frequency F;
- resetting a counter-store to zero each time the position sensor detects the passage from a notch to a tooth;
- accumulating in the counter-store the pulses of frequency F when a tooth is passing the position sensor;
- emptying the counter-store at the frequency F/2 when a notch is passing the position sensor;
- detecting the natural passage of the counter-store through the value zero, this instant corresponding to the falling edge of the absent tooth;
- and
- modifying at said instant the state of a flip-flop.
An apparatus for decoding the angular position of a part driven in rotation integral with a disk provided on its periphery with a succession of mechanically identical teeth and notches and having one tooth removed to constitute an absolute reference, comprising:
- position sensor means adapted to be located next to the periphery of the disk for detecting the passage of the teeth and notches;
- a counter-store;
- pulse generator means for producing a first group of pulse signals at a frequency F and a second group of pulse signals at a frequency of 1/2 F (F/2), the counter-store accumulating pulses at frequency F as long as the position sensor detects a tooth and being emptied at the frequency F/2 as long as the position sensor detects a notch;
- a Schmitt trigger;
- and
- a first monostable multivibrator sensitive to the transition from a notch to a tooth of the input signal;
- the position sensor means being connected to a zero-reset input of a counter-store by the intermediacy of a series connection of the Schmitt trigger and the monostable multivibrator, and the counter-store being connected at an up-down counting input thereof to the output of the Schmitt trigger.
An apparatus for decoding the angular position of a part driven in rotation integral with a disk provided on its periphery with a succession of mechanically identical teeth and notches and having one tooth removed to constitute an absolute reference, comprising:
- position sensor means adapted to be located next to the periphery of said disk for detecting the passage of said teeth and notches;
- Schmitt trigger means coupled to said position sensor for pulse shaping the output of said position sensor, and for producing an output representing the passage of said teeth and notches;
- pulse generator means for producing a first group of pulse signals at a frequency F and a second group of pulse signals at a frequency of 1/2 F;
- counter-store means coupled to said Schmitt trigger means and to said pulse generator means for accumulating pulses at frequency F as long as said position sensor means detects the passage of a tooth, for emptying said counter-store means at the frequency 1/2 F as long as said position sensor means detects a notch, and for producing an output when the contents of said counter-store means is zero, said output representing the passage of said missing tooth;
- and
- monostable multivibrator means coupled to said Schmitt trigger means for detecting the transistor from a notch to a tooth, and for generating a zero-reset signal for said counter-store means upon the detection of said transition.
Dependencies are inferred from the claim text.