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Description Class AreaLight
INTENTION
This class provides all definitions to describe the general aspects of lights in an area. An area is here the generalization of rooms and hallways. In more detail this class provides:
- A set of lights that can be conrolled by the machine. The concrete number of controlled lights can be specified by instantiating the parameter numLights.
- The specification of the behavior of the system concerning the aspect safety. Here safety means that there is sufficient light to move. This class provides the requirements concerning the case that safe light has to be established. Other cases can be considered in derived classes.
- The specification of the behavior of the system concerning the case that the facility manager controls the light using a control panel.
- The specification of the behavior of the system concerning the case that the light is controlled manually.
FORMAL PARAMETERS
Function |
numLights NAT |
Intention |
: |
This parameter represents the number of lights in an area that are controlled by the machine. |
SIGNATURE
Intention |
: |
This object represents the part of the definition of area light defining whether a room is occupied or not. |
Intention |
: |
These objects represent the lights in area that are controlled by the machine. |
Intention |
: |
This object represents the light control panel containing the entities for which the facility manager can enter a value. |
Intention |
: |
This time constant represents the maximal time delay for the following two situations:
- between the time point an area becomes occupied and the time point at which safe light is established;
- between the time point an area becomes unoccupied and the time point the machine controlled lights are off.
|
Intention |
: |
This time constant represents the maximal delay between the time point the machine assumes an occupation of an area and the time point the machine has set the corresponding actuators to establish safe light. |
Timed Predicate |
lightFMControlled |
Intention |
: |
This predicate is true iff the light is controlled by the facility manager using the control panel. |
Timed Predicate |
allLightsOff |
Intention |
: |
This predicate is true iff all lights in an area that are controlled by the machine are off. |
Timed Predicate |
safeLight |
Intention |
: |
This predicate is true, iff there is sufficient light to move safely. |
Timed Predicate |
noSaveLight |
Intention |
: |
This predicate is true iff the light intensity in an area that is occupied can be less than the light intensity needed to establish safe light. This is for example the case if the light is controlled manually. |
Timed Predicate |
manualControl |
Intention |
: |
This predicate is true iff the machine assumes that the light in this area is controlled manually. |
Intention |
: |
This function represents the computation that results in the decision which light has to be on in order to achieve safe light in an area. evalSaveLight[i]=i means that the i-th light has to be on. |
DOMAIN KNOWLEDGE
NL |
: |
The time constant
is allways smaller than the time constant
. |
NL |
: |
The predicate allLightsOff is true iff all lights that are controlled by the machine are off. |
REQUIREMENT SPECIFICATIONS
NL |
: |
Whenever the light is controlled by the facility manager using the control panel and the area is unoccupied for at least
milliseconds, the status of the machine controlled lights equals within this time the status as it is determined by the facility manager. |
NL |
: |
Whenever the light is not controlled by the facility manager using the control panel and the area is unoccupied for at least
milliseconds, all machine controlled lights are off within this time and remains off at least as long as the precondition is true. |
NL |
: |
Whenever safe light has to be established and the area is occupied for at least
milliseconds, the light is sufficient to move safely within this time span and remains sufficient to move safely at least as long as the precondition is true. |
MACHINE SPECIFICATIONS
NL |
: |
Initially safe light has to be established if an area is occupied. |
NL |
: |
Initially the light is not controlled by the facility manager using his control panel. |
NL |
: |
The value of
is always 50 miliiseconds. |
NL |
: |
The value of
is always 30 miliiseconds. |
NL |
: |
The first time delay used to determine occupancy concerning the light control is always 1 second. |
NL |
: |
The second time delay used to determine occupancy concerning the light control is always 0 second. |
NL |
: |
The third time delay used to determine occupancy concerning the light control corresponds always with the value entered by the facility manager for the time a certain area has to be unoccupied continuously before the lights are switched off. |
NL |
: |
The value determined automatically by the machine for occupancy concerning the light control in the case of a malfunction of some sensors used to determine occupancy concerning the light control is occupancy. |
NL |
: |
Whenever safe light has to be established and the area is occupied the necessary actuators, i.e. pulse lines, are set within
milliseconds to establish safe light. |
NL |
: |
The machine assumes that the light is controlled manually in an area iff at least one light in this area is controlled manually and the area is occupied. |
NL |
: |
If the light in an area is controlled manually, the settings of all lights remain unchanged. |
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Forest-System
1999-06-10