GB1567027A - System for locating a plurality of angular positions of a rotating member - Google Patents
System for locating a plurality of angular positions of a rotating member Download PDFInfo
- Publication number
- GB1567027A GB1567027A GB4141776A GB4141776A GB1567027A GB 1567027 A GB1567027 A GB 1567027A GB 4141776 A GB4141776 A GB 4141776A GB 4141776 A GB4141776 A GB 4141776A GB 1567027 A GB1567027 A GB 1567027A
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- signals
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- counter
- alternating
- signal
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
- G01D5/244—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing characteristics of pulses or pulse trains; generating pulses or pulse trains
- G01D5/245—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing characteristics of pulses or pulse trains; generating pulses or pulse trains using a variable number of pulses in a train
- G01D5/2454—Encoders incorporating incremental and absolute signals
- G01D5/2455—Encoders incorporating incremental and absolute signals with incremental and absolute tracks on the same encoder
- G01D5/2457—Incremental encoders having reference marks
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Transmission And Conversion Of Sensor Element Output (AREA)
Description
(54) A SYSTEM FOR LOCATING A PLURALITY OF
ANGULAR POSITIONS OF A ROTATING MEMBER
(71) We, FABBRICA ITALIANA MAGNETI MARELLI S.p.A., an Italian
Company of Via Guastalla 2, Milano, Italy, do hereby declare the invention for which we pray that a Patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement:
This invention is concerned with a system for locating a plurality of angular positions of a rotating member with respect to an angular reference position.
Known are systems for locating angular positions of a rotating member based on detecting a plurality of pulses as determined by particular characteristics of the rotating member as the latter rotates. Such systems require a sensor for sensing an angular reference position and at least another sensor for sensing the other angular positions or fractions of round angle.
It is the object of the present invention to provide a system for locating angular positions of a rotating member, capable of locating any number of angular positions with respect to a predetermined angular reference, by using a single simple sensor, with resulting benefits in wiring simplicity, reliability and cost.
According to the invention, the system for each revolution of the rotating member consists of providing both an alternating reference signal at the angular reference position, and alternating position signals, in opposite phase to the reference signal, at the angular positions; providing at the second half wave of the alternating reference signal and position signals a unidirectional reference signal and unidirectional position signals, respectively; converting said unidirectional position signals into logic signals corresponding to the angular positions of the rotating member relative to the reference position; and using the unidirectional reference signal for controlling the cycle repetition.
The invention will now be disclosed by mere way of example, with reference to the following description and accompanying drawings, in which:
Figure 1 is a largely general block diagram showing the electronic apparatus embodying the system according to the invention;
Figure 2 schematically shows the operation of the apparatus of Figure 1;
Figure 3 is a block diagram showing a particular embodiment of the apparatus of
Figure 1; and
Figure 4 schematically shows the operation of the apparatus of Figure 3.
Referring to Figure 1, reference character
R designates a gear wheel provided with an angular reference element R0 and a plurality of angular position elements Ra, Rb, etc., having characteristics that are uniform to one another, but different from that of R,.
By way of example, element R0 is a tooth, and elements Ra, Rb, etc., are slots formed on the gear wheel periphery..
Said reference and position elements have coupled thereto an electromagnetic fixed simple sensor A, the output of which is directly connected to a discriminatinglimiting device D which, in turn, is connected through two lines L1, L2 to a counter
C.
At each revolution of gear wheel R, sensor A supplies device D both with an alternating reference signal SR and alternating position signals SP (see Figure 2a), the former at the passage of tooth R0 in front of sensor A and the latter at the passage of slots Ra, Rb, etc. in front of said sensor.
Alternating position signals SP are in opposite phase to those of alternating reference signals SR and this, as above stated, is provided by tooth Ro, and slots Ra, Rb, etc.
Device D provides for discriminating the alternating incoming signals SP and SR, so as to supply at its outputs D1 and D2, respectively, unidirectional signals of restricted amplitude SPP and SRP (see Figures 2f and 2g) at the second half cycle of alternating signals SP and SR.
Signals SPP and SRP are supplied to counter C, respectively, through lines L1 and L2 terminating at the inputs El, E2 of counter C (see Figure 1).
Counter C counts position signals SPP, while being reset by reference signals SRP, so as to supply at output U logic signals identifying the several angular positions of elements Ra, Rh, etc. with respect to angular reference position R,.
Figure 3 shows an embodiment of discriminating-limiting device D where gear wheel R is provided with three slots R1, R2 and R3 respectively at 900, 1800, 270 with respect to reference tooth R,. Said device comprises a rectifying-limiting bridge PR having its output 1 connected to input BS1 of a bistable (flip-flop) circuit BS, and its outputs 2 and 3 connected to said counter C through two and gates P1 and P2, enabled to conduct by the output signal of said bistable circuit BS. Inputs 2-3 of rectifying bridge PR have apPlied thereto the alternating signals
SR and SP shown in Figure 4a and which are similar to these of Figure 2a.
Signals SR and SP, as rectified and of restricted amplitude appear between terminals 1-0 of rectifying bridge PR.
Positive amplitude-restricted half cycles of signals SR and SP appear between terminals 2-0 (see Figure 4c), and negative rectified amplitude-restricted half cycles of signals SR and SP appear between terminals 3-0 (see Figures 4d).
Logic signals appear at output BS2 of bistable circuit BS (see Figure 4e), the logic level of which changes at each loading edge of the signals applied to its input BSl. Such logic signals enable gates P1 and P2, so that at the output of gate P1 signals SPP are provided (see Figure 4f) corresponding to the second half waves of alternating position signals SP, and at the output of gate P2 signals SRP are provided (see Figure 4g) corresponding to the second half waves of alternating reference signals SR. Signals
SPP and SRP, similar to those of Figures 2f and 2g, are applied by means of lines L1 and
L2 to inputs E1 and E2 of counter C, the former to be counted and the latter to control counter reset.
With a gear wheel R provided with three slots R1, R2 and R3, a two bit counting capacity will suffice for counter C. In such a case, at the arrival of signals SPP the two outputs a and '3supply logic signals locating the angular positions of elements R1, R2 and
R3 relative to tooth Ro. As shown in Figures 4h and 4i, the logic levels at outputs a and p of counter C are, respectively::
0 0 at the arrival of signal SRP and correspond to the passage of tooth R0 in front of sensor A;
0 1 at the arrival of the first signal SPP and correspond to the passage of slot R1 in front of sensor A, and hence to 90" angle between tooth R0 and slot R1;
10 at the arrival of the second signal
SPP and correspond to the passage of slot
R2 in front of sensor A, and hence to 1800 angle between tooth R0 and slot R2; 11 at the arrival of the third signal SPP and correspond to the passage of slot R3 in front of sensor A, and hence to 2700 angle between tooth R0 and slot R3.
In order to take into account any possible errors of the signals at output of bistable circuit BS, the apparatus shown in Figure 3 further comprises a control counter CR connected to the outputs of and gates P and
P2 and having its outputs a and p fed back to the input of bistable circuit BS through a third and gate P3 having a reversed input and an or gate P4. Of course, in such a case, also output 1 of rectifying bridge PR is connected to the input of bistable circuit BS through OR gate P4.
During correct operation of the apparatus, that is when the logic level of the output signal of bistable circuit BS is right or correct, counter CR counts signals SRP taken off from line L2, while being reset by signals SPP taken off from line L1, the logic signals shown in Figures 41 and 4m appearing at its outputs a' and p', so that at the output of and gate P3 no signal is provided, whereby the only signal applied to bistable circuit BS is the signal from output 1 of rectifying bridge PR.
Should the logic level of output of bistable circuit BS be wrong or incorrect, both due to an initial level opposite to that anticipated, and an incorrect counting start, the output signals of and gates P1 and P2 are no longer those of Figures 4f and 4g, and at outputs a' and p' of counter CR there will appear logic correcting signals which, through AND gate P3 are capable of switching bistable circuit BS to restore its correct logic level.
Reference was made to a gear wheel having three slots and a counter C having a two bit counting capacity, it being of course understood that as the number of slots increases, the counter counting capacity should increase.
Obviously, the operating scheme of the discriminating-limiting device may be differently embodied provided that, supplied by signals SR and SP in the case not necessarily of a sinusoidal nature, it is capable of supplying the counter with signals SPP and
SRP of Figures 2f and 2g.
WHAT IS CLAIMED IS:
1. A system for locating a plurality of angular positions of a rotating member with
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (6)
- **WARNING** start of CLMS field may overlap end of DESC **.respectively, unidirectional signals of restricted amplitude SPP and SRP (see Figures 2f and 2g) at the second half cycle of alternating signals SP and SR.Signals SPP and SRP are supplied to counter C, respectively, through lines L1 and L2 terminating at the inputs El, E2 of counter C (see Figure 1).Counter C counts position signals SPP, while being reset by reference signals SRP, so as to supply at output U logic signals identifying the several angular positions of elements Ra, Rh, etc. with respect to angular reference position R,.Figure 3 shows an embodiment of discriminating-limiting device D where gear wheel R is provided with three slots R1, R2 and R3 respectively at 900, 1800, 270 with respect to reference tooth R,. Said device comprises a rectifying-limiting bridge PR having its output 1 connected to input BS1 of a bistable (flip-flop) circuit BS, and its outputs 2 and 3 connected to said counter C through two and gates P1 and P2, enabled to conduct by the output signal of said bistable circuit BS. Inputs 2-3 of rectifying bridge PR have apPlied thereto the alternating signals SR and SP shown in Figure 4a and which are similar to these of Figure 2a.Signals SR and SP, as rectified and of restricted amplitude appear between terminals 1-0 of rectifying bridge PR.Positive amplitude-restricted half cycles of signals SR and SP appear between terminals 2-0 (see Figure 4c), and negative rectified amplitude-restricted half cycles of signals SR and SP appear between terminals 3-0 (see Figures 4d).Logic signals appear at output BS2 of bistable circuit BS (see Figure 4e), the logic level of which changes at each loading edge of the signals applied to its input BSl. Such logic signals enable gates P1 and P2, so that at the output of gate P1 signals SPP are provided (see Figure 4f) corresponding to the second half waves of alternating position signals SP, and at the output of gate P2 signals SRP are provided (see Figure 4g) corresponding to the second half waves of alternating reference signals SR. Signals SPP and SRP, similar to those of Figures 2f and 2g, are applied by means of lines L1 and L2 to inputs E1 and E2 of counter C, the former to be counted and the latter to control counter reset.With a gear wheel R provided with three slots R1, R2 and R3, a two bit counting capacity will suffice for counter C. In such a case, at the arrival of signals SPP the two outputs a and '3supply logic signals locating the angular positions of elements R1, R2 and R3 relative to tooth Ro. As shown in Figures 4h and 4i, the logic levels at outputs a and p of counter C are, respectively:: 0 0 at the arrival of signal SRP and correspond to the passage of tooth R0 in front of sensor A; 0 1 at the arrival of the first signal SPP and correspond to the passage of slot R1 in front of sensor A, and hence to 90" angle between tooth R0 and slot R1;10 at the arrival of the second signal SPP and correspond to the passage of slot R2 in front of sensor A, and hence to 1800 angle between tooth R0 and slot R2; 11 at the arrival of the third signal SPP and correspond to the passage of slot R3 in front of sensor A, and hence to 2700 angle between tooth R0 and slot R3.In order to take into account any possible errors of the signals at output of bistable circuit BS, the apparatus shown in Figure 3 further comprises a control counter CR connected to the outputs of and gates P and P2 and having its outputs a and p fed back to the input of bistable circuit BS through a third and gate P3 having a reversed input and an or gate P4. Of course, in such a case, also output 1 of rectifying bridge PR is connected to the input of bistable circuit BS through OR gate P4.During correct operation of the apparatus, that is when the logic level of the output signal of bistable circuit BS is right or correct, counter CR counts signals SRP taken off from line L2, while being reset by signals SPP taken off from line L1, the logic signals shown in Figures 41 and 4m appearing at its outputs a' and p', so that at the output of and gate P3 no signal is provided, whereby the only signal applied to bistable circuit BS is the signal from output 1 of rectifying bridge PR.Should the logic level of output of bistable circuit BS be wrong or incorrect, both due to an initial level opposite to that anticipated, and an incorrect counting start, the output signals of and gates P1 and P2 are no longer those of Figures 4f and 4g, and at outputs a' and p' of counter CR there will appear logic correcting signals which, through AND gate P3 are capable of switching bistable circuit BS to restore its correct logic level.Reference was made to a gear wheel having three slots and a counter C having a two bit counting capacity, it being of course understood that as the number of slots increases, the counter counting capacity should increase.Obviously, the operating scheme of the discriminating-limiting device may be differently embodied provided that, supplied by signals SR and SP in the case not necessarily of a sinusoidal nature, it is capable of supplying the counter with signals SPP and SRP of Figures 2f and 2g.WHAT IS CLAIMED IS: 1. A system for locating a plurality of angular positions of a rotating member withrespect to an angular reference position of said member, for each revolution of the rotating member consisting of providing both an alternating reference signal at the angular reference position, and alternating position signals, in opposite phase to the reference signal, at the angular positions; providing at the second half wave of the alternating reference signal and position signals a unidirectional reference signal and unidirectional position signals, respectively; converting said unidirectional position signals into logic signals corresponding to the angular positions of the rotating member relative to the reference position; and using the unidirectional reference signal for controlling the cycle repetition.
- 2. An electronic apparatus embodying the system according to Claim l, the apparatus comprising a rotating member (R) having a reference element (Ro) and a plurality of angular position elements (Ra, Rb) with characteristics that are uniform to one another, but difference from those of said reference element; an input sensor (A) coupled to the reference element (Et") and angular position elements (Ra, Rh) and conditioned to supply at each revolution of said rotating member both an alternating reference signal (SR) and alternating position signals (SP) of opposite phase; a discriminating limiting device (D) connected to said sensor (A) and capable of supplying at each revolution of said rotating member at a first output (D1) thereof unidirectional position signals (SPP) at the second half cycles of said alternating position signals (SP) and at a second output (D2) thereof a unidirectional reference signal (SRP) at the second half cycle of said alternating reference signal (SR); and a counter (C) for counting said unidirectional position signals (SPP) to supply at output (U) logic signals locating the angular positions of said rotating member and which is controlled (reset) by said unidirectional reference signals (SRP) to repeat the cycle (Figures 1 and 2).
- 3. An apparatus according to Claim 2, wherein said discriminating-limiting device comprises a rectifying-limiting device (PR) having a plied thereto said reference signal (SR) and position signals (SP) and supplying relative to ground at a first terminal (1) the two rectified half cycle of the alternating input signals (SR-SP) and at second and third terminals (2, 3) respectively the postion half cycle and negative rectified half cycles of the alternating input signals (SR SP); a bistable (flip-flop) circuit (BS), having applied to its input (BSl) the signals appearing at the first terminal of the rectifying device and supplying at its output (BS2) a signal of a logic level changing at each leading edge of the signals applied to its input; two AND gates (P1, P2), having respectively applied thereto the signals supplied by the second and third terminals of the rectifying device (PR) and enabled by the output signal of said bistable circuit (BS), so that at the output of a gate (PI) there appear the unidirectional position signals SPP) corresponding to the alternating position signals (SP) that are counted by said counter (C), while at the output of the other gate (P2) there appear the unidirectional reference signals SRP) corresponding to the second half cycle of said alternating reference signals (SR) resetting at each cycle said counter (Figures 3 and 4).
- 4. An apparatus according to Claim 3, further comprising a control device for the logic output level of said bistable circuit (BS), reactively connected to the input of said circuit to supply thereto a correcting signal when its output level is wrong or incorrect.
- 5. An apparatus according to Claim 4, wherein said control device comprises a counter (CR) having its input connected to the outputs of said two and gates (P1, P2) and its output connected to the input of said bistable circuit (BS) through a third and gate (P3) and an or gate Or4).
- 6. Appartus for locating a plurality of angular positions of a rotating member with respect of an angular reference position, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB4141776A GB1567027A (en) | 1976-10-06 | 1976-10-06 | System for locating a plurality of angular positions of a rotating member |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB4141776A GB1567027A (en) | 1976-10-06 | 1976-10-06 | System for locating a plurality of angular positions of a rotating member |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1567027A true GB1567027A (en) | 1980-05-08 |
Family
ID=10419593
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB4141776A Expired GB1567027A (en) | 1976-10-06 | 1976-10-06 | System for locating a plurality of angular positions of a rotating member |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB1567027A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL8303063A (en) * | 1983-09-02 | 1985-04-01 | Enschede & Zonen Grafisch | Linear position detector - generates pulsed signals to define position of toothed gear rack |
| GB2158968A (en) * | 1984-05-18 | 1985-11-20 | Monarch Marking Systems Inc | Rotary knife control |
| GB2162645A (en) * | 1984-06-29 | 1986-02-05 | Marelli Autronica | Detecting top dead centre of i.c. engine pistons |
| EP0282884A2 (en) * | 1987-03-18 | 1988-09-21 | Telenorma Gmbh | Position transducer |
-
1976
- 1976-10-06 GB GB4141776A patent/GB1567027A/en not_active Expired
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL8303063A (en) * | 1983-09-02 | 1985-04-01 | Enschede & Zonen Grafisch | Linear position detector - generates pulsed signals to define position of toothed gear rack |
| GB2158968A (en) * | 1984-05-18 | 1985-11-20 | Monarch Marking Systems Inc | Rotary knife control |
| GB2162645A (en) * | 1984-06-29 | 1986-02-05 | Marelli Autronica | Detecting top dead centre of i.c. engine pistons |
| EP0282884A2 (en) * | 1987-03-18 | 1988-09-21 | Telenorma Gmbh | Position transducer |
| EP0282884A3 (en) * | 1987-03-18 | 1989-08-09 | Telenorma Telefonbau Und Normalzeit Gmbh | Sensor for a position transducer |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| CSNS | Application of which complete specification have been accepted and published, but patent is not sealed |