US5239515A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Error-eliminating rapid ultrasonic firing
Assignee: University of Michigan (System)
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Filing: 1991-11-26
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Granted: 1993-08-24
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Expires: 2011-11-26
Abstract
Abstract A system for producing reliable navigation data for a mobile vehicle, such as a robot, combines multiple range samples to increase the "confidence" of the algorithm in the existence of an obstacle. At higher vehicle speed, it is crucial to sample each sensor quickly and repeatedly to gather multiple samples in time to avoid a collision. Erroneous data is rejected by delaying the issuance of an ultrasonic energy pulse by a predetermined wait-period, which may be different during alternate ultrasonic firing cycles. Consecutive readings are compared, and the corresponding data is rejected if the readings differ by more than a predetermined amount. The rejection rate for the data is monitored and the operating speed of the navigation system is reduced if the data rejection rate is increased. This is useful to distinguish and eliminate noise from the data which truly represents the existence of an article in the field of operation of the vehicle.
Inventors
- 👤 Johann Borenstein
- 👤 Yoram Koren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:18
CPC Classifications
G; G01; G01S; G01S15/00; G01S15/88; G01S15/93; G01S15/931; G01S15/02; G01S15/06; G01S15/08; G01S15/10; G01S15/87
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
166 words
A method of operating a sensor element of the type which issues and receives acoustical energy to produce data corresponding to the presence of an article, the method comprising the steps of: triggering the sensor element to issue a first pulse of the acoustical energy; first receiving an acoustical energy at the sensor element; first retriggering the sensor element to issue a second pulse of the acoustical energy upon expiration of a first predetermined period of time after said step of first receiving; second receiving an acoustical energy at the sensor element; second retriggering the sensor element to issue a pulse of the acoustical energy upon expiration of a second predetermined period of time after said step of second receiving; comparing the duration of a first interval between said steps of triggering and first receiving, and the duration of a second interval between said steps of first retriggering and second receiving; and rejecting data as erroneous in response to a difference between said step of comparing.
Claim 2
Independent Claim
166 words
A method of operating a sensor element of the type which issues and receives acoustical energy to produce data corresponding to the presence of an article, the method comprising the steps of: triggering the sensor element to issue a first pulse of the acoustical energy; first receiving an acoustical energy at the sensor element; first retriggering the sensor element to issue a second pulse of the acoustical energy upon expiration of a first predetermined period of time after said step of first receiving; second receiving an acoustical energy at the sensor element; second retriggering the sensor element to issue a pulse of the acoustical energy upon expiration of a second predetermined period of time after said step of second receiving; comparing the duration of a first interval between said steps of triggering and first receiving, and the duration of a second interval between said steps of first retriggering and second receiving; and rejecting data as erroneous in response to a difference between said step of comparing.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein said first and second predetermined periods of time are of unequal durations.
Claim 4
Dependent Claim
37 words
The method of claim 2 wherein after said step of second retriggering, said steps of first receiving, first retriggering, second receiving, and second retriggering are repeated, whereby said first and second predetermined periods of time are alternated.
Claim 5
Dependent Claim
62 words
The method of claim 1 wherein there are provided a plurality of sensors configured as a group of sensors, said group of sensors having a predetermined number of said sensors, said step of triggering occurring sequentially in time for each member of the group, in accordance with a predetermined triggering schedule wherein said first and second predetermined periods of time are alternated.
Claim 6
Dependent Claim
17 words
The method of claim 4 wherein there is further provided a plurality of groups of said sensors.
Claim 7
Dependent Claim
32 words
The method of claim 1 wherein said step of rejecting data as erroneous is responsive to a difference between said first and second intervals being greater than a predetermined period of time.
Claim 8
Dependent Claim
36 words
The method of claim 1 wherein there is further provided the step of controlling a period of time between said steps of first and second retriggering in response to a rate of rejecting data as erroneous.
Claim 9
Independent Claim
268 words
A method of operating an array of ultrasonic sensor elements of the type which issue and receive ultrasonic energy to produce navigation data for a vehicle, the navigation data being responsive to the presence of an article, the method comprising the steps of: defining the array of ultrasonic sensor elements as a plurality of groups of plural ultrasonic sensor elements; triggering a first ultrasonic sensor in each of the groups of ultrasonic sensor elements, to issue a respective first pulse of the ultrasonic energy; first receiving ultrasonic energy at the first ultrasonic sensor element of each group; first retriggering the first ultrasonic sensor element to issue a second pulse of the energy after expiration of a retriggering period of time for the first ultrasonic sensor element having a duration corresponding to a combined predetermined firing cycle period and a first predetermined period of wait-time; triggering a second ultrasonic sensor element in each of the groups of ultrasonic sensor elements, to issue a respective first pulse of the ultrasonic energy after expiration of a predetermined associated schedule period, said predetermined schedule period having a duration which is less than that of said predetermined firing cycle period; first receiving ultrasonic energy at the second ultrasonic sensor element of each group; and first retriggering the second ultrasonic sensor element in each group to issue a respective second pulse of the energy after expiration of a retriggering period of time for the second ultrasonic sensor element having a duration corresponding to the combination of the predetermined firing cycle period, a further predetermined associated schedule period, and a first predetermined period of wait-time.
Claim 10
Independent Claim
268 words
A method of operating an array of ultrasonic sensor elements of the type which issue and receive ultrasonic energy to produce navigation data for a vehicle, the navigation data being responsive to the presence of an article, the method comprising the steps of: defining the array of ultrasonic sensor elements as a plurality of groups of plural ultrasonic sensor elements; triggering a first ultrasonic sensor in each of the groups of ultrasonic sensor elements, to issue a respective first pulse of the ultrasonic energy; first receiving ultrasonic energy at the first ultrasonic sensor element of each group; first retriggering the first ultrasonic sensor element to issue a second pulse of the energy after expiration of a retriggering period of time for the first ultrasonic sensor element having a duration corresponding to a combined predetermined firing cycle period and a first predetermined period of wait-time; triggering a second ultrasonic sensor element in each of the groups of ultrasonic sensor elements, to issue a respective first pulse of the ultrasonic energy after expiration of a predetermined associated schedule period, said predetermined schedule period having a duration which is less than that of said predetermined firing cycle period; first receiving ultrasonic energy at the second ultrasonic sensor element of each group; and first retriggering the second ultrasonic sensor element in each group to issue a respective second pulse of the energy after expiration of a retriggering period of time for the second ultrasonic sensor element having a duration corresponding to the combination of the predetermined firing cycle period, a further predetermined associated schedule period, and a first predetermined period of wait-time.
Claim 11
Dependent Claim
53 words
The method of claim 8 wherein there are further provided the steps of: second receiving ultrasonic energy at each first ultrasonic sensor element; and second retriggering the first ultrasonic sensor element to issue a pulse of the energy upon expiration of a second predetermined period of wait-time after said step of second receiving.
Claim 12
Dependent Claim
18 words
The method of claim 8 wherein said first and second predetermined periods of wait-time are of unequal durations.
Claim 13
Dependent Claim
42 words
The method of claim 10 wherein after said step of second retriggering, said steps of first receiving, first retriggering, second receiving, and second retriggering are repeated during subsequent firing cycle periods, whereby said first and second predetermined periods of wait-time are alternated.
Claim 14
Independent Claim
290 words
A method of operating an array of ultrasonic sensor elements of the type which issue and receive ultrasonic energy to produce navigation data for a vehicle, the navigation data being responsive to the presence of an article, the method comprising the steps of: defining the array of ultrasonic sensor elements as a plurality of groups of plural ultrasonic sensor elements; first triggering simultaneously each ultrasonic sensor element in a first group of the ultrasonic sensor elements, to issue a respective first pulse of the ultrasonic energy for each ultrasonic sensor element therein; first triggering simultaneously each ultrasonic sensor element in a second group of ultrasonic sensor elements, to issue a respective first pulse of the ultrasonic energy for each ultrasonic sensor element therein after expiration of a schedule period from the time of first triggering the first group of the ultrasonic sensor elements and upon further expiration of a first predetermined period of wait-time; first retriggering simultaneously the ultrasonic sensor elements in the first group of ultrasonic sensor elements to issue a second pulse of the energy after expiration of a retriggering period of time for the ultrasonic sensor elements in the first group having a duration corresponding to a combined predetermined firing cycle period and a predetermined period of wait-time; and first retriggering simultaneously the ultrasonic sensor elements in the second group of ultrasonic sensor elements, to issue a second pulse of the ultrasonic energy after expiration of a retriggering period of time for the ultrasonic sensor elements in the second group having a duration corresponding to the combination of the predetermined firing cycle period and a predetermined associated schedule period, said predetermined schedule period having a duration which is less than that of the predetermined firing cycle period.
Claim 15
Independent Claim
290 words
A method of operating an array of ultrasonic sensor elements of the type which issue and receive ultrasonic energy to produce navigation data for a vehicle, the navigation data being responsive to the presence of an article, the method comprising the steps of: defining the array of ultrasonic sensor elements as a plurality of groups of plural ultrasonic sensor elements; first triggering simultaneously each ultrasonic sensor element in a first group of the ultrasonic sensor elements, to issue a respective first pulse of the ultrasonic energy for each ultrasonic sensor element therein; first triggering simultaneously each ultrasonic sensor element in a second group of ultrasonic sensor elements, to issue a respective first pulse of the ultrasonic energy for each ultrasonic sensor element therein after expiration of a schedule period from the time of first triggering the first group of the ultrasonic sensor elements and upon further expiration of a first predetermined period of wait-time; first retriggering simultaneously the ultrasonic sensor elements in the first group of ultrasonic sensor elements to issue a second pulse of the energy after expiration of a retriggering period of time for the ultrasonic sensor elements in the first group having a duration corresponding to a combined predetermined firing cycle period and a predetermined period of wait-time; and first retriggering simultaneously the ultrasonic sensor elements in the second group of ultrasonic sensor elements, to issue a second pulse of the ultrasonic energy after expiration of a retriggering period of time for the ultrasonic sensor elements in the second group having a duration corresponding to the combination of the predetermined firing cycle period and a predetermined associated schedule period, said predetermined schedule period having a duration which is less than that of the predetermined firing cycle period.
Claim 16
Dependent Claim
32 words
The method of claim 12 wherein said predetermined period of wait-time has a first duration during every other predetermined firing cycle period, and a second duration the remaining predetermined firing cycle periods.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-08-23 | 1997-02-22 | 1997-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-23 | 2001-02-22 | 2001-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-23 | 2005-02-22 | 2005-08-24 | $7700.00 | Window Closed / Lapsed |