US3922671A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Position measurement system with provision for change of units of measurement
Assignee: Inductosyn Corp
•
Filing: 1974-06-17
•
Granted: 1975-11-25
•
Expires: 1994-06-17
Abstract
Abstract A position measurement system is disclosed including an improved pulse-width modulator in which positive and negative modulation counters respectively provide first and second modulator pulses having a time displacement therebetween proportional to a displacement between relatively movable members of a transducer. The modulation counters can be loaded to store signals representative of a cumulative number of least changes of the displacement, and clock pulses are provided to the modulation counters whereby the modulator output pulses are generated. The time displacement between the output pulses is changed in proportion to the cumulative number of the least changes stored by the counters. This arrangement permits the modulator counters to be modified in a predetermined fashion so that the least indicated change can represent alternatively a quantity in one of a plurality of measurement systems, e.g. in inch or metric units. In making this conversion, however, the delay in which data changes are recognizable in the output is not thereby increased and the effective information rate of the system is maintained.
Inventors
- 👤 Robert W Tripp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:17
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/12; H03M1/22; H03M1/24; H03M1/28; H03M1/30; H03M1/303; H03M1/305
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
247 words
In a position measurement system having a position measurement transducer and means responsive to said transducer for generating a tracking pulse representative of a least change in the position of two relatively movable members of said transducer, further having a pulse-width modulator responsive to said tracking pulse for providing to said transducer an output pulse having a pulse-width proportional to said position, said modulator including a clock pulse source which provides clock pulses to first and second modulation counters of a type which stores a signal representation of a number which is increased in response to a clock pulse and provides a modulator pulse concurrently with storing a signal representation of a predetermined maximum number, said modulation counters being connected to an output circuit which provides a Sine output pulse having a pulse-width proportional to a time displacement between corresponding portions of said first and second modulator pulses, the improvement comprising: positive accumulation means responsive to said tracking pulse for storing a signal representation of a positive base number which is changed in response to a tracking pulse, said positive base number being representative of a cumulative change of said position; and loading means responsive to said positive accumulation means for loading said first modulation counter to store in said first modulation counter said signal representation of a positive base number, whereby the pulse-width of said sine output pulse is altered by an amount proportional to said cumulative change of said position in a predetermined measurement system.
Claim 2
Dependent Claim
247 words
In a position measurement system having a position measurement transducer and means responsive to said transducer for generating a tracking pulse representative of a least change in the position of two relatively movable members of said transducer, further having a pulse-width modulator responsive to said tracking pulse for providing to said transducer an output pulse having a pulse-width proportional to said position, said modulator including a clock pulse source which provides clock pulses to first and second modulation counters of a type which stores a signal representation of a number which is increased in response to a clock pulse and provides a modulator pulse concurrently with storing a signal representation of a predetermined maximum number, said modulation counters being connected to an output circuit which provides a Sine output pulse having a pulse-width proportional to a time displacement between corresponding portions of said first and second modulator pulses, the improvement comprising: positive accumulation means responsive to said tracking pulse for storing a signal representation of a positive base number which is changed in response to a tracking pulse, said positive base number being representative of a cumulative change of said position; and loading means responsive to said positive accumulation means for loading said first modulation counter to store in said first modulation counter said signal representation of a positive base number, whereby the pulse-width of said sine output pulse is altered by an amount proportional to said cumulative change of said position in a predetermined measurement system.
Claim 3
Dependent Claim
54 words
A position measurement system according to claim 1 wherein said loading means further comprises circuit means for loading said first modulation counter to store a predetermined reference number signal representation associated with a predetermined measurement system whereby a least change in said output sine pulse is proportional to one unit in said measurement system.
Claim 4
Dependent Claim
103 words
A position measurement system according to claim 1 wherein said first modulation counter includes higher order stages and lower order stages which respectively provide higher order and lower order signals, said signals being respectively representative of a lower order number which is increased in response to a clock pulse and a higher order number which is increased in response to said lower order stages providing a lower order signal representation of a modulus number, said loading means comprising: means for loading said lower order stages to store said positive base number signal representation in response to said signal representation of said modulus number.
Claim 5
Dependent Claim
82 words
A position measurement system according to claim 3 wherein said positive base number is increased and decreased in response to tracking pulses respectively representative of an increase and a decrease of said position in a predetermined direction, additionally comprising: negative accumulation means for providing a signal representation of a negative base number which is decreased and increased, respectively, in response to said tracking pulses; and means for causing said second modulation counter to store a signal representation of said negative base number.
Claim 6
Dependent Claim
27 words
A position measurement system according to claim 1 wherein said output circuit additionally provides a cosine output pulse having a pulse-width complementary to said sine output pulse.
Claim 7
Dependent Claim
208 words
A position measurement system according to claim 2 for providing an indication in metric units of a displacement between relatively movable members of said transducer, wherein said tracking pulse is generated in response to a least change in Imperial units, said modulator including similar first and second modulation counters which respectively provide first and second modulator pulses in response to clock pulses provided at a known frequency, each modulation counter providing a modulator pulse in response to a known number of clock pulses, a time displacement between corresponding portions of said modulator pulses being proportional to said displacement, said modulator additionally comprising a reference counter which provides a reference pulse train in response to said clock pulses and a reference pulse in response to said known number of clock pulses, comprising: circuit means for modifying said first and second modulation counters to cause the provision of said modulator pulses in response to 2.54 times said known number of clock pulses, said circuit means further comprising: means for providing to said modulation counters clock pulses at a clock pulse frequency which is 2.5 times said known frequency; and means for providing to said reference counter clock pulses at a clock pulse frequency which is 125/127 times said known freQuency.
References Cited (Backward Citations)
US3742487A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |