Nichols chart
E187945
A Nichols chart is a graphical design tool used in control engineering to analyze and shape the closed-loop frequency response by plotting open-loop gain versus phase on contour maps of constant closed-loop magnitude.
All labels observed (2)
| Label | Occurrences |
|---|---|
| Nichols plot | 2 |
| Nichols chart canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T1651074 — 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: Nichols chart Context triple: [Bode plot, relatedTo, Nichols chart]
-
A.
Nyquist plot
The Nyquist plot is a graphical representation used in control engineering and signal processing to assess the stability and frequency response of linear time-invariant systems by plotting complex gain as a function of frequency.
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B.
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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C.
Nyquist stability criterion
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.
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D.
Bode
The Bode is a river in central Germany that flows through the Harz Mountains and Saxony-Anhalt before joining the Saale.
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E.
Bode
Bode is a surname most notably associated with Hendrik Wade Bode, an influential American engineer and pioneer in control theory and communication systems.
- 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: Nichols chart Target entity description: A Nichols chart is a graphical design tool used in control engineering to analyze and shape the closed-loop frequency response by plotting open-loop gain versus phase on contour maps of constant closed-loop magnitude.
-
A.
Nyquist plot
The Nyquist plot is a graphical representation used in control engineering and signal processing to assess the stability and frequency response of linear time-invariant systems by plotting complex gain as a function of frequency.
-
B.
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.
-
C.
Nyquist stability criterion
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.
-
D.
Bode
The Bode is a river in central Germany that flows through the Harz Mountains and Saxony-Anhalt before joining the Saale.
-
E.
Bode
Bode is a surname most notably associated with Hendrik Wade Bode, an influential American engineer and pioneer in control theory and communication systems.
- F. None of above. chosen
Statements (46)
| Predicate | Object |
|---|---|
| instanceOf |
control engineering tool
ⓘ
frequency response analysis method ⓘ graphical design tool ⓘ |
| advantage |
convenient for loop-shaping design
ⓘ
direct visualization of closed-loop performance from open-loop data ⓘ simultaneous assessment of gain and phase margins ⓘ |
| alsoKnownAs |
Nichols chart
ⓘ
surface form:
Nichols plot
|
| appliesTo |
linear time-invariant systems
ⓘ
single-input single-output systems ⓘ |
| assumes | steady-state sinusoidal response ⓘ |
| canBeExtendedTo | multi-loop systems ⓘ |
| coordinateSystem | gain versus phase ⓘ |
| domain | frequency domain ⓘ |
| enables |
graphical controller parameter adjustment
ⓘ
trade-off analysis between performance and robustness ⓘ |
| field |
control engineering
ⓘ
control theory ⓘ |
| hasFeature |
contour maps of constant closed-loop magnitude
ⓘ
loci of constant closed-loop response ⓘ |
| horizontalAxis | phase ⓘ |
| input | open-loop frequency response ⓘ |
| namedAfter | Nathaniel B. Nichols NERFINISHED ⓘ |
| output | closed-loop magnitude information ⓘ |
| plots | gain in dB versus phase in degrees ⓘ |
| relatedTo |
Bode plot
ⓘ
Nyquist plot ⓘ root locus ⓘ |
| represents |
contours of constant closed-loop magnitude
ⓘ
open-loop gain ⓘ open-loop phase ⓘ |
| usedFor |
closed-loop frequency response analysis
ⓘ
complementary sensitivity shaping ⓘ controller tuning ⓘ feedback control system design ⓘ gain and phase margin evaluation ⓘ loop-shaping design ⓘ robustness analysis ⓘ sensitivity shaping ⓘ stability analysis ⓘ |
| usedIn |
aerospace control systems
ⓘ
classical control design ⓘ industrial process control ⓘ servo system design ⓘ |
| verticalAxis | gain in decibels ⓘ |
| visualizes |
effect of gain changes on closed-loop response
ⓘ
effect of phase lag and lead on closed-loop response ⓘ |
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: Nichols chart Description of subject: A Nichols chart is a graphical design tool used in control engineering to analyze and shape the closed-loop frequency response by plotting open-loop gain versus phase on contour maps of constant closed-loop magnitude.
Referenced by (3)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Nichols plot
this entity surface form:
Nichols plot