JPS6324443A - Event scheduling system - Google Patents

Abstract

PURPOSE:To flexibly set and execute various time relations between events by setting a relational expression between the start time and the completion time of the respective events. CONSTITUTION:A time parameter consisting of a start time variable and a completion time variable and a completion flag are set with respect to the respective events, the time relation with the respective events is represented by the network of the time parameter and the relational expression between the time parameters of the contacts of both the ends is attached to the branch of the network. At a certain time, whether the respective events are executed or not is decided according to the comparison of the value of the time parameter and the time or to the completion flag. At the time of the start or the completion of the certain event, the network of the time parameter is successively traced and the value of the time parameter of other event related to the event is decided according to the relational expression, thereby, the synchronization of the respective events is taken.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a scheduling method for arbitrary events on a total of X machines, such as events in computer simulations and operations in computer animations.

(Prior Art) The event referred to here is any event on a computer, and in particular, it can be an event that occurs at a certain time in a computer simulation, or the movement of an object.

It is assumed that an event starts at a certain time (start time) and ends at a certain time (end time), and the time relationship between multiple events is set by the sequential relationship between their start time and end time. If an event starts at a certain time t1, the start time of the event may be set to tl. Also, event A is event B
If the start time of event A is started later than the start time of event B, the start time of event A may be set to a value later than the start time of event B. Also,
By setting a qualitative magnitude relationship between the start time or end time of each event, the start time of an event can be determined based on the time relationship with other events, without having to clearly set the start time of an event. It was also possible to do so.

For example, use the predicate hold to set the event event to start executing at time time, and set h
old(event, time) Furthermore, a predicate was provided to express the time relationship between events, and a schedule was set using this predicate. For example, the fact that event A occurs before event B is expressed as follows using the predicate before.

before (A, B) For details, see Mizoguchi et al., [Prototype of an action planning system including time information J (Information Processing Society of Japan 32nd (first half of 1985) National Conference Proceedings pp, 1559-1560).

(Problem to be solved by the invention) However, although the above method was able to describe qualitative temporal relationships such as the simultaneity and order of an event A and another event B, for example, It was not possible to include a quantitative value in the time relationship, such as starting 4 seconds after the start.

Furthermore, the time relationships are described using predicates that have been preliminarily prepared, and the user cannot freely set various time relationships.

It is an object of the present invention, in order to solve the above problems, to set a relational expression between the start time and end time of each event, and to use the relational expression to determine the time relationship between each event not only qualitatively but also quantitatively. It is an object of the present invention to provide an event scheduling method that can flexibly set and execute various time relationships between events by using various relational expressions.

(Means for resolving interlocking points) The event scheduling method of the present invention sets a time parameter consisting of a start time variable and an end time variable, and an end flag for each of the above events, and Express the time relationship of the above as a network of the above time parameters, attach relational expressions between the time parameters that are the contact points of both ends of the above branches to the branches of the above network, and express the presence or absence of each of the above events at a certain time as the above. time parameters of other events related to said event, by comparing the value of the parameter with said time, or as determined by said end flag, traversing said network one after another at the start or end time of an event; The present invention is characterized in that the above-mentioned events are synchronized by determining the value of according to the above-mentioned relational expression.

(Operation) In the present invention, for each of the above events, a time parameter consisting of a start time variable and an end time variable, and
An end flag is set, the time relationship with each of the above events is expressed by a network of the time parameters, and the branches of the network are attached with relational expressions between the time parameters that are the contact points at both ends of the technique. Whether each of the above events is executed at a certain time is determined by comparing the value of the time parameter with the time, or by using the end flag. If the value of the start time variable is greater than or equal to the current time, execution is executed, and if the value of the end time variable is smaller than the current time or the end flag is activated, execution is completed. At the start or end time of a certain event, the time-related network described above is followed one after another, and the values of the time parameters of other events related to the above event are determined by the above relational expression, thereby determining the value of each of the above events. Can be synchronized.

(Example) Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a conceptual diagram showing an example of the time relationship of occurrence of events. The start time and end time of each event are shown on the time axis. In this figure, event A starts at time L1 and ends at time L2. Event B starts at time t2 and ends at time t4.
ends at Event C starts at time t3 and ends at time L5. The event begins at time t4 and ends at time t6. Here, each time tl, . . . , t6 may have an undetermined value. Therefore, for example, if time t2 is undetermined, then FIG. 2 expresses the qualitative property that event B starts at the same time as event A ends. Similarly, if t2 = t3, it means that event B and event C start at the same time t2 (t2.t
If 3 is undetermined, [it expresses only the qualitative temporal relationship of simultaneous j. ).

FIG. 3 is an explanatory diagram for representing the contents of the event. The content of the event consists of a name, an execution body representing the execution content of the event, a start time variable name, an end time variable name, and an end flag.

The name of the event can be any unique name that can be distinguished from other experiences. The execution body stores the contents to be executed by various events.

In FIG. 3, as an example, execution contents for printing the character "hello" are stored. The start time variable name is a pointer to a storage area for storing the start time, and the value of the start time variable is either directly given by the user or determined by a time synchronization mechanism described later. The end time variable name is a pointer to a storage area for storing the end time. The value of the end time variable is determined in the same way as the start time variable. These two variables are collectively referred to as the time parameter, and the event schedule is set by this time parameter.

However, the value of the time parameter is not necessarily determined in advance, and may be dynamically determined based on the time relationship with other events. The details will be described later. Finish flags indicate that events have fulfilled their purpose during execution.

The end flag is activated by the events themselves when the processing of the execution body ends. When the end flag is activated, the events are ended, and the time at that time is stored in the end time variable.

Events are classified into standby events and execution events based on their status.

A standby event is one that has not yet occurred at the time T of interest and is in a state of waiting to start. An execution event is one that is already being executed at time T. Waiting events are registered in the waiting event list, and execution events are registered in the execution event list. In the initial state of scheduling (time 0 or any reference time), all events are first registered in the waiting event list. Furthermore, when an event is actually caused by a device such as a computer according to the time relationship shown in FIG. 2, the time axis becomes discrete, and the time is counted in units of time.

FIG. 1 is a block diagram showing the entire event scaling method as an embodiment of the present invention. Event storage means 1 for storing and referencing the contents of events; event execution determination means 2 for determining whether the event of interest will be executed or terminated at a certain time; A time synchronization means 3 for synchronization, an event execution means 4 for executing the event execution body, and a clock generation means 5 for providing time are provided. A connection IA 6 for inputting the contents of an event to the event storage means 1, a connection line 7 for transmitting the contents of the event stored in the event storage means 1 to the event execution determination means 2, and an event execution determination means 2.
A connection line 8 for transmitting state transition information indicating whether execution of the event generated in is on standby to the event storage means 1, and time parameters (start time variable and end time variable) in the event execution determination means 2.
A connection line 9 for transmitting time synchronization information consisting of the value and the current time to the time synchronization means 3, and a connection line 1o for transmitting the time parameter value determined by the time synchronization means 3 to the event storage means 1. , a connection line 11 for transmitting information on whether or not to execute the event determined by the event execution determination means 2 and the time at that time to the event execution means 4, and a connection line 12 for outputting the execution result τ of the event execution means 4. A master line 13 is provided to transmit the time generated by the clock generation means 5 to the event execution determination means 2.

The contents of the event shown in FIG. 3 are stored in the event storage means l shown in FIG. When storing, a table for event reference is generated by combining the event name and the address of the storage area where the event content is stored.

FIG. 4 is a flowchart showing the procedure of event scaling, and shows the processing in the event execution determination means 2, time synchronization means 3, and event execution means 4 of FIG. A scaling method for a certain event X at a certain time T will be described below as an example. In step 101, from the value of the time parameter of the event X and the time T, the event
is executed at time T. If event X starts exactly at time T, synchronization with other events is performed based on the start time variable of event X and time T. Details will be described later. If it is determined that step 10 is to be executed, step 102 advances the process to step 103 for execution, the execution body of event X is executed, and then in step 104 event X ends at time T. Determine. If it is determined in step 101 not to be executed, the process proceeds directly to step 104 in step 102, and it is determined whether event X ends at time T. If it is determined in step 104 that the event has ended, synchronization with other events is performed based on the end time variable of event X and time T. Details will be described later.

The above explanation is based on a certain event X at a certain time T.
However, at a certain time [T1.
T2], the process shown in FIG. 4 may be repeated for each event at each time T while advancing time T by one unit time from time T1 to time T2. However, there is no need to perform a start check for events registered in the execution event list.

FIG. 5 is a flowchart for explaining step 101 of the start check in FIG. 4 in detail. Consider time T. First, in step 21, it is checked whether the value of the start time variable ts of event X has already been determined but is still undetermined. To indicate that it is undetermined, an undetermined flag may be given to ts. If it is undetermined, it is assumed that event X will not be executed at time T, and event X will remain registered in the waiting event list. If ts is determined, step 2
2, the value of ts and time T are compared in magnitude. ts
If the value of is greater than time T, it is assumed that event X has not yet started at time T, and remains registered in the waiting event list. If the value of 75 is less than or equal to time T, it remains registered in the waiting event list. If the value of ts is less than or equal to time T, it is interpreted as being executed. At this time, if it is determined in step 23 that the value of ts is equal to time T, the event is taken. A method for synchronizing will be described later. ° Events interpreted in step 22 to be executed are moved in step 25 from the waiting events list to the running events list.

FIG. 6 is a flowchart for explaining step 104 of the completion check in FIG. 4 in detail. Consider time T. First, in step 31, it is checked whether the end time variable te of the event X is undetermined or determined (this is done in the same manner as the start check). If te is determined, the value of te and time T are compared in step 32, and if te is less than or equal to T, time synchronization with other events is established based on te and time T in step 35. . If te is undetermined, but te>T, it is checked in step 33 whether the end flag of event X is on.

The end flag is activated by the events themselves when the processing of the execution body ends. If the end flag is activated, it is assumed that event X ends at time T, and step 3
In step 4, the value of the end time variable te of event X is set to T, and in step 35, synchronization with other events is established. If the termination flag is not activated, it will not terminate. Step 32
Alternatively, if it is determined in step 33 that the event has ended, event X is removed from the running event list and the waiting event list in step 36.

Next, a method of setting time relationships between events will be explained.

An example of a method for setting time relationships between events is shown in FIG.

In FIG. 7, the time relationship of the events shown in FIG. 2 is taken as an example. In FIG. 2, t1=3 and t2. t3゜t4. t
,5. Although t6 is undetermined, t3-t2 = 2,
Assume that t5-1,4 = 3. It is expressed using the predicate occur that event A starts at time 3. The predicate se indicates that event B starts immediately after event A.
In q, the predicate 5tart means that event C starts at the second time unit after the start of event B, the predicate finish means that event C ends at the third unit time after the end of event B, and event B
The predicate seq expresses that the event starts immediately after .

Based on the time relationships set as above, a network of time parameters consisting of start time variables and end time variables is constructed, and synchronization between events is achieved by propagating the values of the time parameters on the network. .

Next, a method of synchronizing events using a time-related network will be explained. A time-related network has a form in which time parameters are connected by directed edges, and a certain calculation formula is attached to the directed edges. The time parameter on the starting point side of the directed branch will be called an active variable, and the time parameter on the end point side of the directed branch will be called a dependent variable. FIG. 8 is an explanatory diagram illustrating an example of a method for configuring a network related to time of events. FIG. 8 shows a network configuration method corresponding to the setting method of FIG. 7. However, regarding the predicate occur,
Simply assign 3 to the start time variable of the target event A. Therefore, there is no corresponding column in FIG. The network is configured as a triple table of active variable names, dependent variable names, and calculation formulas. When a value is stored in the active variable, the calculation result of the calculation formula is stored in the corresponding dependent variable.

Further, if the dependent variable is also registered as an active variable, similar processing is performed using the dependent variable as the active variable. That is, the result of a value stored in a certain variable is propagated one after another on the network. Therefore, when a certain event starts or ends, the values of the time parameters of various events and the time parameters of other events connected on the network are determined one after another, and the times are synchronized.

FIG. 9 is a flowchart illustrating an example of a procedure for propagating values on a network of time-related events. Now, suppose that values are propagated on the network starting from a time parameter tp (which may be a start time variable or an end time variable). First, in step 41, a propagation path on the network starting from tp is determined. To find the propagation path, based on the table in Figure 7, with tp as the active variable, list all the corresponding dependent variables and pairs of calculation formulas ((tl, E
l), (t2. E2), -(tn, En)) and use this as the search route list. However, tl.

t2. ..., tn is a time parameter, El, E2.
..., En are calculation formulas corresponding to each time parameter. Next, tl.

t2. ..., tn as active variables, find all the corresponding pairs of dependent variables and calculation formulas in the same way as above,
Merge into the already desired search route list. However, time parameters already on the search route list are excluded. By repeating the above operations one after another, the propagation path is found (this is basically a horizontal search.The search algorithm is, for example, in the literature self-explained by Tsujii,
Artificial Intelligence (Sonic Shoten, 1982), Chapter 3. ). Based on the propagation list obtained in step 41, the values of the time parameters are propagated in step 42. Value propagation can be accomplished by sequentially extracting pairs of time parameters and calculation formulas from the propagation list, and storing the calculation results of the calculation formulas in the time parameters.

(Effects) As described above, the event scheduling method of the present invention sets a relational expression between the start time and end time of each event, and uses the relational expression to determine the time relationship between each event not only qualitatively but also quantitatively. Furthermore, by using various relational expressions, various time relations between events can be flexibly set and executed. therefore,
Time relationships between events can be set in detail, improving schedule setting ability.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the entire implementation method of the present invention;
Figure 2 is a conceptual diagram showing an example of the time relationship of events, Figure 3 is an explanatory diagram showing the contents of events, Figure 4 is a flowchart showing the procedure for event scheduling, and Figure 5 is an event at time T. 6 is a flowchart showing an example of a method for checking the start of an event at time T. FIG. 7 is a flowchart showing an example of a method for checking the end of an event at time T. FIG. An explanatory diagram, FIG. 8 is an explanatory diagram showing an example of a method for configuring a time-related network of events, and FIG.
The figure is a flowchart showing an example of a procedure for propagating the value of a time parameter on an event time relationship network.

Claims (1)

[Claims] In the event scheduling method, a relational expression is set between the start time or end time of each of the above events, and at the start or end time of an event, the start time or end time of another event related to the above event is set. An event scheduling method characterized in that events are determined one after another using the above relational expressions.