# bla2.txt

The flashcards below were created by user mrpoodle21 on FreezingBlue Flashcards.

1. Dynamical system
systems where the effect of a certain action only becomes visable, or reaches a steady state, after some time
2. Model
Simplified dicription of a system, just complex enough to describe or study the phenomena that are relevant for our problem contect
3. Control system
System with a feedback loop to keep certain quantities constant (e.g. temperature of thermostat in house)
4. Elementary system
System>subsystem>sub(sub)system>sub(subsub)system>>elementary system
5. Bileteral interaction
System where the action of one subsystem leads to a reaction of the other subsystem
6. a-causal model
Same relations as causal relation diagram but without choosing what we consider as cause and effect
7. Positive feedback
8. Discrete systems
Systems that are described at fixed, discrete, time intervals
9. Continuous-time systems (question 3 on practice exam)
System with an input signal and feedback. A typical property is the memory function. This memory determines the state of the system (the amount of something at a certain moment, e.g. water in a tank) In a continuous time system the memory in an integrator. The output value of an integrator can be used as a state variable.
10. Transient responses or transients
Graphs which show how a system goes from equilibrium state to another
11. Capacitor
• Can be seen as battery, stores electrical energy
• q = it
• q = charge of battery, i = constant
• If i is not constant:
12. Inductor
Coil of wire, stores energy in the form of a magnetic field
13. Inductance
Property that belongs to a coil.
14. Magnetic flux
the magnetic flux through a surface is the component of the magnetic field passing through that surface
When the coil has n windings the so-called flux linkage is equal to the product of the number of windings and the magnetic flux. Capacitor stores electrical energy in the form of electrical charge, an inductor, in the form of coil, in the form of flux linkage.
16. Transfer function
A mathematical representation of the relation between the input and output of a linear time-invariant system with zero initial conditions and zero-point equilibrium.
17. Water hammer
Can be observed when water is flowing through a pipe and the flow at the end of the pipe is cut off.
18. Elementary physical models
Elementary subsystem of a component
19. Ideal Physical Model (IPM)
Model solely built of elementary physical models (basically a 20-sim model)
20. Lumped paramaeter
model Dominant physical behavior of a model represented by a limited number of interconnected ideal physical elements
21. Static equilibrium
Gravity firce will be compensated by the force of a spring
22. Moment of inertia
= mass moment of inertia = angular mass
23. Transfer function
Function with delay operator
24. Gyrator
Used as a transducer between different physical domains.
25. Ideal voltage source
• Element that delivers constant voltage
• Must have an internal resistance of zero
26. Power
P = ui
27. Modulated voltage source
Modulated by sinusoidal signal.
28. Ideal current source
• Element that delivers constant current
• Must have a large internal resistance
29. Node
Point where two or more elements are connected
30. Path
Formed by a number of interconnected circuit elements
31. Transducer
Element that couples multiple domains (a.g. electrical en mechanical e.g. electric engine)
32. Sensor
• Transducer that is able to convert physical quantities
• extract information from the system in the form of a digital signal
33. Actuator
Converts signals into physical quantities (modulated volatage source)
34. Power conjugated variables
Variables with the dimension of power in watts
35. One-port element
Elements for which there is a single variable which determines the flow of energy to and from this element
36. Two-port element
Elements that change the ratio between u and I of F and v, but the product P remains constant
37. Bonds
Half arrows, presents energy flow
38. 1-junction
• Neutral symbol 1 which replaces the domain-dependent variables I and v
• Represents heat flows
39. 0-junction
Represents temperatures
40. Bilateral signal flow
Represented by a bond that combines two signals
41. Actuator
Element that converts signals to power (e.g. modulated voltage source)
42. Commutation
The process of inverting the direction of the current
43. Counter electromotive force
Voltage that is proportional to the angular velocity
44. Tachogenerator
Sensor to measure angular velocity
45. Component
Consists of physical elements, which under certain circumstances may be left out of the model
46. Rectification
The process of converting elements from AC to DC
47. Diode
Suppresses the negative parts of the sine wave
48. Diode bridge
Converts the negative parts of the sine waves to positive ones
49. Double-sides rectification or full-wave rectification
Extra diodes that ensure that both parts of the sinusoidal signal contribute to charging the capacitor
50. Ramp signal
??
51. Feed-forward control
Real condition at the end of a process has no influence on the actual duration of the process
52. Fuzzy controller
Observation with no real values (a bit longer, much shorter, )
53. Proportional gain
Depends on another variable (like approaching a red traffic light, the distance varies)
54. Overshoot
Proportional gain doesnt work (driver brakes too late and crosses the stopping line)
55. Derivative control
Another variable is needed because there was an overshoot. This will be velocity. Velocity is derived from the position
56. Control engineering
The art of tuning the parameters of a controller
57. Unstable system
oscillations increase or exponential growth
58. Op-amp
Operational amplifier
59. Active component
Component with external power supply
60. Non-inverting input
Positive input of an amplifier
61. Inverting input
Negative input of an amplifier
Circuit which can make the weighted sum of two or more input signals
63. Passive circuit
Circuit with only resistor, capacitors and inductances
64. Low-pass filter
Filter that passes low frequencies
65. Pneumatic controllers
Controller which uses compressed air to carry a signal
66. Hydraulic systems
Used when high forces are needed
67. Soft real time performance
Performance is fast enough
68. Hard real time performance
Performance is fast enough and at fixed time intervals
69. Embedded computer
Computers you dont see (implemented in microwaves etc), fitted with embedded control systems
70. Digital control systems
Embedded control systems
Analog to digital converter
72. Hold circuit
Equipped in DA-converter. Circuit that holds the voltage until a new conversion is performed
73. Zero-order hold
Hold circuit where the voltage is kept at a constant value
74. Sampling rate
T,sample = t,dominant/10
75. Aliasing
Happens when sampled with a too low sampling frequency. The frequency of the sine wave will change
76. Nyquist rate
2* the highest frequency
77. ρ
flow
78. ζ
Damping ratio
79. Φ
Magnetic flux
80. λ
81. L
Self-inductance
82. q
Charge
83. ω
Angular velocity
84. Se
Voltage source
85. Hookes law
• Relation between the force F acting on a spring and the deformation of the spring, the change in length x:
• F = kx
• k = the spring constant
• also correct:
• x=1/k*F or x=cF
• c = 1/k = the compliance
86. Newtons law
• F = ma
• a = (1/m)* F
• F = ma = m(d(v)/dt)
87. Ohm`s law
u = Ri
88. Kirchoffs law
• Sum of all currents = 0
• Sum of all voltages = 0
89. dAlemberts law
The algebraic sum of all forces acting on an object in a mechanical system and the time derivative of the impulse of the object equals zero.
 Author: mrpoodle21 ID: 223552 Card Set: bla2.txt Updated: 2013-06-12 14:06:08 Tags: klsadäf Folders: Description: sldfglksjdf Show Answers: