Sampled Data System¶
A feedback system couples a continuous plant to sampled observation, digital control updates, and returned actuation across intersample intervals.
Core Idea¶
A sampled data system is a feedback loop around a continuously changing plant. A digital controller observes the plant at discrete instants, computes an updated command, and sends it back to affect the plant. The plant continues to evolve between observations. A CNC servo drive and a modeled chemical reactor show this same arrangement with different physical processes.[ref-895947443036][ref-e42db1f8e018]
Scope of Application¶
The identity requires five linked roles: a continuous-time plant, sampled output observation, digital control update, returned actuation, and intersample evolution. A fixed sampling period and a zero-order hold occur in the two cases below, but neither is universal; non-uniform sampled-data control is also studied. A sampled-equivalent model is an analysis tool, not a required physical part.[ref-895947443036][ref-e42db1f8e018][^ref-578de4bb293a]
Clarity¶
Ask whether a measured plant output helps change a later input to that same continuous plant. A sensor log samples but does not close a control loop. An analog feedback controller may close a loop without discrete observation and digital updating. A wholly discrete plant has no continuous behavior between updates. These distinctions keep sampling, feedback, and this particular hybrid system separate.[^ref-5f2d8cf01b3b]
Manages Complexity¶
The five roles show where an engineering claim belongs. Sample timing, controller law, return interface, and plant motion can be examined separately. Koren and Bollinger study sample rate and servo gain against stability, contouring accuracy and bandwidth in their particular machine-tool design. The reactor paper analyzes a different continuous plant and sampled approximation; its relative-degree issue is not a universal behavior of every sampled system.[ref-895947443036][ref-e42db1f8e018]
Abstract Reasoning¶
To classify a candidate, trace a continuous plant output to a discrete observation, through a digital law, then back as a plant input. Ask what occurs before the next observation and which model justifies any stability or performance claim. Remove the return path and the arrangement becomes one-way measurement. Remove the continuing plant dynamics and the intersample question disappears.[^ref-5f2d8cf01b3b]
Knowledge Transfer¶
The CNC motor and reactor do not share physical equations, but both use the same output-to-input loop across a digital/continuous interface. Their role pattern can guide analysis of another eligible control system, while their sensor hardware, controller gains and simulation results cannot simply be copied. The broad portable return-loop pattern belongs to the approved Feedback Prime; the named sampled-data system remains a control-engineering specialization.[ref-895947443036][ref-e42db1f8e018]
Example¶
CNC machine-tool servo. Koren and Bollinger describe a motor and axis that keep moving between fixed sampling instants. Feedback from the Fig. 1 digital encoder arrangement is sampled and processed by a computer; an output register and digital-to-analog converter return a held drive reference. Mapped roles: plant → motor and axis; observation → sampled feedback; update → computer-generated reference; return interface → register and converter acting as zero-order hold; intersample evolution → continuing motion relevant to the studied accuracy and stability. The encoder and fixed period are features of this design, not class requirements.[^ref-895947443036]
Continuously stirred-tank reactor. Di Ciccio, Bottini and Pepe model a continuous reactor, use sampled reactor information in a digital feedback law, and apply the command through a zero-order hold. Mapped roles: plant → original continuous reactor model; observation → sampled reactor variables; update → digital control law; return interface → hold applying its input; intersample evolution → reactor dynamics continuing between updates. Their sampled approximation has a stated relative-degree distinction from the continuous model. The paper's model and simulations do not establish a deployed sensor, valve or controller installation.[^ref-e42db1f8e018]
Relationships to Other Abstractions¶
Current abstraction Sampled Data System Domain-specific
Parents (1) — more general patterns this builds on
-
Sampled Data System is a kind of Feedback Prime
A sampled plant output is routed through a digital control update to a subsequent plant input.
Hierarchy path (1) — routes to 1 parentless root
- Sampled Data System → Feedback
Neighborhood in Abstraction Space¶
Sampled Data System sits in a sparse region of the domain-specific corpus (93rd percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.
Family — Unclustered & Miscellaneous (2551 abstractions)
Nearest neighbors
- Repetitive Control — 0.86
- Local Time (Mathematics) — 0.78
- Kinetic Scheme — 0.77
- Dead-beat control — 0.77
- Work Output — 0.77
Computed from structural-signature embeddings · 2026-10-08
Not to Be Confused With¶
Sampling (signal processing) and data acquisition may supply observations without feedback. An open-loop sequence of digital commands lacks output return. Neither periodic sampling nor zero-order hold defines every member of the class. The sole approved strict parent is Feedback, because every admitted instance returns output information to a later input, whereas Feedback also occurs without a digital sampled interface.[^ref-578de4bb293a]
References¶
[^ref-895947443036]: Yoram Koren and John G. Bollinger, Design Parameters for Sampled-Data Drives for CNC Machine Tools, IEEE Transactions on Industry Applications IA-14(3) (May/June 1978), pp. 255–264, especially abstract, Fig. 1 and Introduction (printed p. 255). [^ref-e42db1f8e018]: M. P. Di Ciccio, M. Bottini and P. Pepe, Digital Control of a Continuous Stirred Tank Reactor, original publisher article (17 April 2011), DOI 10.1155/2011/439785, especially continuous model §2 and digital-control discussion §3. Publisher indexed passages were available for the stated roles; hardware beyond those passages is not asserted. [^ref-5f2d8cf01b3b]: Yutaka Yamamoto, I. Sampled-Data Systems, From Lifting to Frequency Response, IEEJ Transactions on Electronics, Information and Systems 114(7–8) (1994), pp. 729–734, DOI 10.1541/ieejeiss1987.114.7-8_729. The original title is “I. Sampled-Data Systems: From Lifting to Frequency Response”; the linked comma transcribes that punctuation for citation binding. Used for the continuous-time/intersample distinction, not for CNC or CSTR hardware. [^ref-578de4bb293a]: Xian-Ming Zhang, Qing-Long Han, Xiaohua Ge, Boda Ning and Bao-Lin Zhang, Sampled-data control systems with non-uniform sampling, A survey of methods and trends, Annual Reviews in Control 55 (2023), pp. 70–91, DOI 10.1016/j.arcontrol.2023.03.004. Title originally punctuated with a colon after “sampling.” Abstract supports the non-uniform-sampling scope point only.