Nyquist stability criterion
E36214
The Nyquist stability criterion is a graphical frequency-domain method in control theory used to determine the stability of feedback systems by analyzing how their open-loop transfer function encircles a critical point in the complex plane.
All labels observed (2)
| Label | Occurrences |
|---|---|
| Nyquist stability criterion canonical | 13 |
| Nyquist criterion | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T274193 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Nyquist stability criterion Context triple: [negative feedback amplifier, usesConcept, Nyquist stability criterion]
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A.
Bode plot
A Bode plot is a graphical representation of a linear system’s frequency response, showing magnitude and phase versus frequency on logarithmic scales, widely used in control and amplifier design.
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B.
von Neumann stability analysis
Von Neumann stability analysis is a mathematical technique used in numerical analysis to determine the stability of finite difference schemes for solving partial differential equations by examining the growth of Fourier modes.
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C.
Dynamic Systems and Control Division
The Dynamic Systems and Control Division is a technical division of the American Society of Mechanical Engineers focused on the modeling, analysis, and control of dynamic engineering systems.
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D.
Differential analyzer
The Differential Analyzer is an early analog mechanical computer designed to solve differential equations using interconnected rotating shafts and wheels.
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E.
A Loop
A Loop is a modern streetcar route in Portland, Oregon, that provides circulator service through the central city and adjacent neighborhoods as part of the Portland Streetcar system.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Nyquist stability criterion Target entity description: The Nyquist stability criterion is a graphical frequency-domain method in control theory used to determine the stability of feedback systems by analyzing how their open-loop transfer function encircles a critical point in the complex plane.
-
A.
Bode plot
A Bode plot is a graphical representation of a linear system’s frequency response, showing magnitude and phase versus frequency on logarithmic scales, widely used in control and amplifier design.
-
B.
von Neumann stability analysis
Von Neumann stability analysis is a mathematical technique used in numerical analysis to determine the stability of finite difference schemes for solving partial differential equations by examining the growth of Fourier modes.
-
C.
Dynamic Systems and Control Division
The Dynamic Systems and Control Division is a technical division of the American Society of Mechanical Engineers focused on the modeling, analysis, and control of dynamic engineering systems.
-
D.
Differential analyzer
The Differential Analyzer is an early analog mechanical computer designed to solve differential equations using interconnected rotating shafts and wheels.
-
E.
A Loop
A Loop is a modern streetcar route in Portland, Oregon, that provides circulator service through the central city and adjacent neighborhoods as part of the Portland Streetcar system.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
control theory concept
ⓘ
frequency-domain method ⓘ stability criterion ⓘ |
| analyzes | open-loop transfer function ⓘ |
| appliedIn |
aerospace engineering
ⓘ
chemical process control ⓘ communication systems ⓘ electrical engineering ⓘ mechanical engineering ⓘ |
| appliesTo |
feedback control systems
ⓘ
linear time-invariant systems ⓘ |
| assumes |
system is linear
ⓘ
system is time-invariant ⓘ transfer function is rational ⓘ |
| basedOn | Nyquist plot ⓘ |
| canDetermine | marginal stability ⓘ |
| canHandle |
systems with right-half-plane poles
ⓘ
systems with time delay ⓘ |
| category |
feedback stability methods
ⓘ
graphical analysis techniques in control ⓘ |
| comparedWith |
Bode stability criterion
ⓘ
Routh–Hurwitz stability criterion ⓘ |
| coreConcept |
encirclement of the critical point -1+0j in the complex plane
ⓘ
relationship between open-loop poles and closed-loop stability ⓘ |
| determines | absolute stability ⓘ |
| domain | frequency domain ⓘ |
| field |
control theory
ⓘ
systems engineering ⓘ |
| historicalPeriod | 20th century ⓘ |
| input | open-loop frequency response ⓘ |
| namedAfter | Harry Nyquist ⓘ |
| output | stability conclusion ⓘ |
| relatedConcept |
closed-loop pole locations
ⓘ
root locus method ⓘ small-gain theorem ⓘ |
| relatedTo |
Bode plot
ⓘ
closed-loop characteristic equation ⓘ gain margin ⓘ phase margin ⓘ |
| relates | number of encirclements to right-half-plane poles ⓘ |
| requires | Nyquist contour in the complex plane ⓘ |
| teachingContext |
graduate control theory courses
ⓘ
undergraduate control systems courses ⓘ |
| usedFor |
determining closed-loop stability from open-loop data
ⓘ
stability analysis of feedback systems ⓘ |
| uses |
argument principle from complex analysis
ⓘ
mapping of contours under a complex function ⓘ |
| visualizedBy |
Nyquist diagram
ⓘ
linked to:
Nyquist plot
|
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Nyquist stability criterion Description of subject: The Nyquist stability criterion is a graphical frequency-domain method in control theory used to determine the stability of feedback systems by analyzing how their open-loop transfer function encircles a critical point in the complex plane.
Referenced by (14)
Full triples — surface form annotated when it differs from this entity's canonical label.
subject linked to:
Harry
subject linked to:
Nilsby, Värmland County, Sweden
linked to: Nyquist stability criterion