# Shared Flashcard Set

## Details

ELE709 Post Midterm
Ryerson ELE709: Real-Time Computer Control System
22
Engineering
12/03/2008

Term
 What is the Closed-Loop Online Method (Ultimate Sensitivity)?
Definition
 1. Turn off I and D (Tc->inf; Td=0). 2. Increase slowly until system is marginally stable. 3. The value of Kp when the system is marginally stable is Ku.
Term
 What is the Modified Closed-Loop Online Method (1/4 decay)?
Definition
 1. Turn off I and D action. 2. Apple a step input. 3. Adjust Kp until the step response has the 1/4 decay property. 4. This value of Kp is called Km.
Term
 What are the three approaches for CT to DT?
Definition
 A. Numerical integration/differentiation. B. Pole-Zero matching. C. Hold equivalent.
Term
 What is the solution for Numerical Integration/Differentiation?
Definition
 y(kT)=y((k-1)T)+ int from {(k-1)T} to {kT} {[-ay(t)+au(t)]dt}
Term
 What is the forward rectangular rule?
Definition
 T[-ay((k-1)T)+au((k-1)T)] and in z: Gc(z)=Gc(s)|s=(z-1)/T
Term
 What is the backward rectangular rule?
Definition
 T[-ay(kT)+au(kT)] and in z: Gc(z)=Gc(s)|s=(1-z^-1)/T
Term
 What is Tustin's method (Trapezoid Rule)?
Definition
 (T/2)[-ay((k-q)T)+au((k-1)T)-ay(kT)+au(kT)] and in z: Gc(z)=Gc(s)|s=(2/T)[(z-1)/(z+1)]
Term
 What is the solution for Pole-Zero Matching?
Definition
 1. Convert real poles s=a to z=e^(aT) 2. Convert complex poles s=a+jb to z=re^(jtheta) 3. take finite zeros and step 1 and 2 them. 4. infinite zeros are mapped to z=-1. 5. Gc(z)|z=1
Term
 What is the solution for hold equivalence?
Definition
 Gc(z)=(1-z^-1)Z[Gc(s)/s]
Term
 What is PID and what is the practical PID controller?
Definition
 P=Kp.e(t) I=Kp.[1/(Ti)] int from 0 to 1 {e(t)dt} D=Kp.Td(de(t)/dt) or P=Kp I=Kp/(ti.s) D=Kp.Td.s For practical PID controller: Kp.Td.s.E(s) is replaced by E(s).(Kp.Td.s)/(1 + td.s/N) for the derivative term (D in PID)
Term
 What is schedulable?
Definition
 If there exist enough processor cycles to execute all the tasks.
Term
 What is meant by a feasible scheduling algorithm?
Definition
 The possibility to allocate the tasks so that all the deadlines are met.
Term
 What is meant by an optimal algorithm?
Definition
 One which will produce a feasible schedule if it exists.
Term
 What is an cyclic executive (CE) approach to scheduling?
Definition
 An execution schedule for tasks created before run-time and a program controls execution of tasks according to this schedule.
Term
 What is FIFO?
Definition
 Tasks are inserted at the end of a ready list and then execution taken from the beginning of the list but can not be preempted.
Term
 What is RR?
Definition
 Round Robin. Similar to FIFO, but tasks are preempted when its time runs out and then re-inserted at the end of the ready list.
Term
 What is RM?
Definition
 Rate monotonic. For a set of independent tasks, they are assigned fixed priorities based on its period. The shorter the period, the higher the priority will be assigned.
Term
 What is DM?
Definition
Term
 What is EDF?
Definition
Term
 What would be potential problems for dependent tasks?
Definition
 1. Deadlock. 2. Priority Inversion. 3. Transitive blocking.
Term
 What is OPCP?
Definition
 Original Priority Ceiling Protocol. Each task has a static default priority assigned and a dynamic priority that is inherited from blocking higher priority tasks. Each resource has a static priority ceiling value. A task can only lock a resouce if its dynamic priority is higher than the ceiling value of any currently locked resource.
Term
 What is IPCP?
Definition
 Immediate priority ceiling protocol. Like OPCP but the dynamic priority is raised to PC(R) as soon as there is a successful lock.
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