Glossary of terms. Short explanation

Transcription

1 Glossary Concept Module. Video Short explanation Abstraction 2.4 Capturing the essence of the behavior of interest (getting a model or representation) Action in the control Derivative 4.2 The control signal is proportional to the error derivative Integral 4.2 The control signal is proportional to the error integral Proportional 4.2 The control signal is proportional to the error Actuator 3 Element generating the manipulated variable based on the control signal Algorithm 2.2, 2.3 Implementable step by step procedure to compute a function Analogy 2.2 Similarity in the dynamic behavior of systems and signals, independently of their technological support Analysis 6 Process of extracting properties of a model Anti wind-up 4.3 Limiting the integral action to avoid saturation Automation 1.2, 5.2 Automatic generation of control signals (usually on-off) to manage a complex system Autonomous system 2.2 Evolves by itself, without manipulated variables (solar system, or UAV- unmanned aerial vehicle) Balance 2.2 Process variables balance (of mass, flow, force ) Bio-inspired systems 5.3 Systems designed following the behavior of natural elements or systems Block diagram 2.3 Representation where elements/subsystems are represented by boxes and signals by arrows Blood glucose regulation system 1.1 Regulation system of glucose level in blood Car washing system 1.2 Automatic car washing plant Communication 4 Sending information between two (or more) locations Control 1.1 Select the actions to get a desired behavior Adaptive 4.3 The control algorithm is adapted based on information about the process model obtained on-line Cancellation 4.2 The controller, in series with the plant, cancels some terms of

2 the plant operator Cascade 4.1, 4.3 There are two (or more) controllers controlling internal variables accessible to be measured. Each controller generates the reference for the next. The outer one is the master controller Collaborative 5.3 The information from different internal variables is used by different controllers to generate the corresponding control signals Coordinated 4.1 The set points of different control loops are determined to fulfill a global goal Event-based 5.3 The control is computed any time an event happens Feedforward 4.1 The control information flows in one direction, from external data/commands to the plant input Goal oriented 3.4 The control actions are generated to achieve a global goal Hierarchical 4.1 Different goals, at different level of aggregated information, are nested to achieve a global goal Intelligent 4.3, 5.3 The control action is generated by using AI techniques (fuzzy logic, Neural networks, ) Loop 4.1 Control when implemented by fed backing information from the process Model Predictive 4.3 The control action is computed (in an optimal way) based on the plant model and expected reference Necessary 5.1 If the plant is open-loop unstable Networked systems 4.3, 5.3 The control signals as well as the measurements are delivered through a communication network On/Off 4.2 Simple control with two options (relay) PID 4.2 The control action is proportional to the error, its derivative and its integral Remote 5.1 Control goals are fixed (can be based on received information from the plant) locally and transmitted Robust 4.3 When the control is acceptable for a wide range of process models (parameters) Supervisory 4.1 The loop generating the set-point for a lower level control System 3 Subsystem generating the control actions Two-degrees-of- 4.1 One controller in the loop, for disturbance rejection, and one

3 freedom controller in the feedforward path, for reference tracking. Controller 4 Component delivering the control action based on information about requirements and behavior Cyber-physical systems 5.3 Systems where sensing, information processing and actuation devices are integrated in a physical process. Delay operator 2.3 Transforms a signal into the same but time-delayed Design (control) 4, 6 Process of determining the structure and parameters of the control system Discretization 2.4 Approaching the CT behavior of a system/signal by its DT representation Disturbance 3.2 External variable not manipulated Disturbance rejection 3.4 Control design to reject the effect of disturbance on the controlled variables Embedded systems 5.3 Sensing, computing and actuation components embedded in a larger device. Error 3 Difference between the reference and the controlled variable Estimation 4 Based on the model of a process and the information attached to it, compute the current or future values of internal variables Experimental modeling 2.3, 6 Obtaining the model of a process from experimental data Factory automation 1.2 Integrated control of different subprocesses to achieve an ultimate goal (quality tiles factory) Feedback 3, 1.1, Information from a process used to generate its input First principles 2.2 Basic knowledge to establish variables relationships Homeostasis 1.1 Human system in which variables are regulated remaining stable and relatively constant Information flow 2.1 Logical and temporal dependency of signals Initial conditions 2.2 System s variables value when an external signal is applied Instability 3 Inability to keep around a given equilibrium point Integrated design 6 Design of the control and its implementation on a computing system Interaction 2.1 Directional influence between elements or processes. Laplace transform 2.3, 2.4 Converts a continuous time signal in the time domain to the s- domain

4 Linear 2.3 It applies for systems, operators, operations: Follows the principles of superposition and proportionality Loop closed 4.1 When there is a feedback open 4.1 When the information flows in one single direction Manipulated Variable 1.2 External variable determined by the control Measurement 3.1 Information related to a process variable Memory 1.1 The current situation depends on the past Model 2.2 Partial representation of a system/signal Noise 2.2 The undesirable content of a signal Noise filtering 3.4 Reducing the effect of the noise in the estimated process variables Nonlinear 2.2 Opposite to linear Observer 4.3 Dynamic system used to estimate some internal variables not directly measurable (estimator, filter) Operator 2.2 Mathematical transformation of signals Optimization 3.4 Algorithm to design the control to optimize a performance index Parameters 1.3 (Physical) magnitudes unchanged while observing Performance Quality of behavior Psychological processes 1.1 Human processes related to motivation, cognition and emotion Real time 1.2 When information should be treated within time limits Reference 3.2 Set point or signal to be tracked Regulation 3.2 Control system to keep the controlled variable as less sensitive as possible to inner and outer changes Regulator 3.2 The device providing the control action Representation 1.3, 2, 6 Equivalent information suitable to be handled response Steady -state response Transient The stabilized output under stationary inputs The transient behavior under changes in the inputs Robotics 3.2 Science dealing with robots Robustness 3.4 Capability to keep the controlled system performance under

5 changes in the process Sensitivity The relative change in a signal or operator under small changes in an external signal or a parameter Sensor 3.2 Component providing information related to a variable of interest Servosystem 3.2, 5.2 Control system to make the controlled variable to track a reference signal, in spite of disturbances Signal 1.3, 2.1 Time variant magnitudes Binary 2.1 A signal with only two possible values Continuous time 2.1 A signal taking value at any time instant Discrete time 2.1 A signal taking value at discrete time instants External/internal 2.1 Signal generated without/with influence of the process Input/output 2.1 External/measured signal Simulation 2.1, 6 Study of a system by running a model Stability 3 Capability to keep the state of a process around an equilibrium point or nominal trajectory State 3 Set of process variables defining the current situation Steady-state error 4.2 Error in the process once the transient vanishes System 2.1 Set of elements interacting among them and with the environment Complex 1.2, 4.3 Systems with many components and interactions Continuous time 2.1 The variables of interest are continuous time Discrete time 2.1 The variables of interest (control) are discrete time Dynamic 1.1 A system where the current value of some internal variables depend on past values of system variables Generator 1.3 Process used to generate required signals: sinusoidals, steps, ramps Hybrid 2.1 There are mixed CT and DT signals Processor 1.3 The purpose is to process a signal (filter, sampler ) Reactive 1.1 The control actions try to react to changes in the environment Static 1.1 A system where the current value of the internal variables only depend on the current values of the input variables

6 Unstable 3, 5.1 A system requiring control actions to keep a fixed position System s structure 2.1 The way in which the different elements interact - Loop 2.1 There is a feedback of information - Parallel 2.1 Several elements have the same input and the outputs are added - Series 2.1 The output of an element is the input of the next System s Variables 1.3 Signals linked to a process Tele-operation 5.1 Control actions are sent by communication channels, also receiving information from sensors Tracking 1.2 A system created to follow a given reference Transfer function 2.3 Operator representing the relation between two signals (in the s-domain) Transmitter 1.3 A device to send information through cable or air Virtual sensor 4.3 A sensor providing information about an internal variable based on the measured inputs and outputs Water cycle 1.1 Evolution of the water in Nature Watt s regulator 2.3 A pioneer reference for an industrial controller Z transform 2.3, 2.4 Converts a discrete time signal in the time domain to the z- domain