KR101073430B1 - Method of invoking asynchronous function for controlling robots and system therefor - Google Patents

Abstract

The asynchronous function call method of the present invention relates to an asynchronous function call method for controlling a mechanical device, the method comprising: receiving a request to perform an asynchronous operation according to an asynchronous function call; Immediately returning a result according to the asynchronous operation execution request and returning a control object capable of controlling the asynchronous operation of the asynchronous function; Checking whether an asynchronous operation is performed through the returned control object to determine whether it is in a cancelable state; If the asynchronous operation execution state is a cancelable state, checking whether a forced cancellation request is received; And if the forced cancellation request is received, forcibly canceling the asynchronous operation. According to the present invention, it can be commonly used in all programs that use asynchronous function calls to control mechanical devices, and asynchronous function calls are frequently used, such as applications that control mechanical devices such as robots through computer programs. To facilitate the work of developers in the application.

Asynchronous, function, call, control, object, result, error

Description

Method of invoking asynchronous function for controlling robots and system therefor}

The present invention relates to an asynchronous function call method for robot control. More specifically, the present invention relates to a method of asynchronous function call, which is useful when controlling a mechanical device such as a robot which frequently performs a long-running operation through a program.

The present invention is derived from the research conducted as part of the IT growth engine core technology development project of the Ministry of Knowledge Economy and the Ministry of Information and Communication Research and Development. [Task management number: 2008-S-029-01, Task name: RUPI-Server technology development] .

In general, a robot has three functional elements that sense an external environment, make a determination based on sensed information, and act according to a determination result, and have devices for processing these functions. However, in order to add various functions to the robot or to add new functions, complicated configurations and expensive equipment are required, and thus it is difficult to provide various functions and the cost burden increases.

Therefore, recently, a network robot system for distributing functions in a robot through a network has been developed to provide a more inexpensive robot.

In general, a network robot system is composed of a distributed system consisting of a server and a plurality of robot clients. Network communication in such a distributed system is achieved through message exchange between distributed systems utilizing communication middleware. These middlewares are combined with object-oriented concepts to provide remote object invocation, and various methods such as DCOM, COBRA, RMI, and XML Web Services have been proposed and used.

On the other hand, asynchronous function calls have been studied in the existing IT field. For example, asynchronous method invocation (AMI) has been mentioned in RPC (Remote Procedure Call) based communication middleware such as COBRA.

However, most of the techniques or researches are closely related to the process of asynchronous operation processing in the function call interface, and thus, there is a problem that the interface cannot be used when other asynchronous function call methods are used.

Unlike a synchronous function call, 'asynchronous function call' does not wait for the result value of the function to be calculated and returned after the function call, but instead of returning the control to process the next function call (or command). Calling method. Therefore, asynchronous function calls have functional and performance advantages, such as increased program responsiveness, compared to synchronous function calls. However, reliable asynchronous function call methods are presented in detail such as checking the status of a function call executed asynchronously, obtaining a result value, and detecting an error when an asynchronous function is executed. It was not going.

In the case of a function call executed asynchronously, it is impossible to write a reliable program unless the function described above is provided.

In particular, when controlling a mechanical device such as a robot through a remote program, it is very urgent to provide a reliable asynchronous function call method.

The present invention is designed to solve the above problems,

By defining a non-dependent asynchronous function call interface, asynchronous functions for robot control that can be commonly used in all programs that frequently use asynchronous function calls, such as applications that control machine devices such as robots through computer programs. Its purpose is to provide a calling method.

The asynchronous function call method of the present invention relates to an asynchronous function call method for controlling a mechanical device, the method comprising: receiving a request to perform an asynchronous operation according to an asynchronous function call; Immediately returning a result according to the asynchronous operation execution request and returning a control object capable of controlling the asynchronous operation of the asynchronous function; Checking an asynchronous operation execution state through the returned control object to determine whether it is in a cancelable state; If the asynchronous operation execution state is a cancelable state, confirming whether a forced cancellation request is received; And if a forced cancellation request is received, forcibly canceling the asynchronous operation.

In particular, when the forced cancellation request is not received, the method may further include acquiring a result value of performing the asynchronous operation through the returned control object and providing the result to the caller.

The method may further include determining a cause of an error occurring during the asynchronous operation using the result value of the asynchronous operation.

The acquiring of the asynchronous operation execution result value may include waiting until the asynchronous operation execution is completed and obtaining a result value of the asynchronous operation execution if the asynchronous operation execution is not finished.

The checking of the asynchronous operation execution state may include checking the asynchronous operation execution state by a polling method through the returned control object.

In addition, the checking of the state of performing the asynchronous operation includes whether the calling asynchronous function has been started, whether the calling asynchronous function has completed successfully, whether the calling asynchronous function has been interrupted due to an error during execution, and calling It is characterized by checking whether one or more asynchronous functions are forcibly canceled during execution.

The checking of the asynchronous operation execution state may include checking the asynchronous operation execution state by a callback method through the returned control object.

In addition, when the forced cancellation request is received, forcibly canceling the asynchronous operation may be performed by receiving a cancellation reason as a string from a rigid body cancellation requester requesting the forced cancellation.

According to the present invention has the following effects.

The asynchronous function call interface referred to in the present invention has an advantage of describing various asynchronous function call interfaces regardless of the asynchronous operation processing method.

In addition, the method proposed in the present invention can be commonly used in all programs using asynchronous function calls. Therefore, it is possible to facilitate the developer's work in an application program where asynchronous function calls are frequently used, such as applications that control a mechanical device such as a robot through a computer program.

The present invention will now be described in detail with reference to the accompanying drawings. Here, the repeated description, well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention, and detailed description of the configuration will be omitted. Embodiments of the present invention are provided to more completely describe the present invention to those skilled in the art. Accordingly, the shape and size of elements in the drawings may be exaggerated for clarity.

Hereinafter, the asynchronous function call method according to the present invention will be described in detail with reference to the drawings.

1 is a diagram for explaining a state transition of called asynchronous functions.

The asynchronous function called follows the state transition as shown in FIG.

'PENDING' state of reference numeral 10 indicates that the asynchronous function is called, but there is a thread that fails to start when there is a thread using the same resource. Of course, whether to wait for an asynchronous function may vary depending on the asynchronous operation scheduler.

Next, the called asynchronous function waits in the 'PENDING' state, and when all the threads ahead of it finish using the resource, it is allocated the resource and starts to perform the asynchronous operation. 'Transition to state.

If the operation of the called asynchronous function completes successfully, it transitions to 'COMPLETED' state as indicated by reference numeral 30. However, if the operation of the called asynchronous function is not completed successfully and is terminated, the state transitions to the 'FAILED' state of reference numeral 40. For example, in the case of controlling a mechanical device such as a robot, an error frequently occurs, and thus often a case in which operation of the called asynchronous function cannot be performed successfully is terminated.

In general, a function that causes the driving of a mechanical device requires a relatively long execution time compared to other function calls. For example, when the robot moves, moves, or reads a sentence, the execution time requires several seconds to several minutes. In the present invention, such a function call will be defined as a 'long term execution operation'. Since general operations are performed synchronously, they wait until the execution is completed. However, for long-running operations, control is returned immediately after the request, and the function can be checked later if desired. Therefore, you must make asynchronous function calls. Because an asynchronous function call returns control immediately after the call, the developer may be forced to cancel the function if necessary. If the execution time is longer than a few seconds, the necessity of canceling the function becomes more and more. As such, an asynchronous function call can be canceled at any time, except when the developer has already completed or failed after the call. That is, the developer can cancel the operation of the called asynchronous function at any time unless the execution state of the called asynchronous function is the 'COMPLETED' state of the reference numeral 30 or the 'FAILED' state of the reference numeral 40.

Referring to FIG. 1, it is possible to forcibly cancel in the 'PENDING' state of the reference numeral 10 and the 'RUNNING' state of the reference numeral 20. When the operation of the asynchronous function called by the forced cancellation request is minimized, the state immediately transitions to the 'CANCELLING' state of reference numeral 50. Here, the canceling operation for asynchronous operation may vary depending on the function call contents and the asynchronous function processing method.

After the cancel operation is completed through the 'CANCELLING' state of reference numeral 50, the state transitions to the 'CANCELED' state of reference numeral 60.

2 is a view for explaining the structure of an asynchronous operation layer in the asynchronous function call system according to the present invention. 3 illustrates an interface of an object that controls asynchronous function calls implemented using the Java language.

In the asynchronous function call system according to the present invention, the asynchronous operation layer returns control immediately after a request for a long-running operation such as driving, moving, or reading a sentence, and asynchronous operation so that the result can be checked later if desired. This is the layer to perform. In this case, the asynchronous function is defined as an operation handle type and returns an object of a long-running operation. In other words, these operation handles provide an interface to check the status, control, and obtain the results of a long-term asynchronous operation.

The asynchronous operation layer is divided into an operation handler 100 and an operation adapter 120, and the operation adapter 120 includes a scheduler 122.

The scheduler 120 provided in the operation adapter 120 allocates one work thread to an asynchronous operation request according to an asynchronous function call, and performs one asynchronous operation object stored in a queue.

The operation handler 100 is responsible for asynchronous operation processing defined as an interface of the operation handle, and requests the operation adapter 120 to perform asynchronous operation.

More specifically, the operation handler 100 is a progress check unit 112 for checking the execution state of the asynchronous function called, a call result obtaining unit 114 for obtaining a call result of the asynchronous function called, calling An exception processing unit 116 for identifying error information generated during the execution of the asynchronous function, and a forced cancellation processing unit 118 forcibly canceling the called asynchronous operation execution function.

First, the asynchronous function must be able to check the execution status of the asynchronous function that it calls because the control returns after the call and before the operation of the asynchronous function completes. Accordingly, the present invention provides an interface for checking the operation execution state of the asynchronous function called through the progress state checking unit 112.

Reference numeral 101 in FIG. 3 shows an interface for querying to check the execution state of the called asynchronous function. That is, query methods to check the operation execution status of called asynchronous function. You can use 'isStarted ()' to check whether the asynchronous function has actually started, and 'isCompleted ()' to check whether the asynchronous function has completed its operation successfully. And, through 'isFailed ()', you can check whether the abortion is interrupted due to an error while performing asynchronous function operation, and 'isCanceled ()' to check whether the asynchronous function is forcibly canceled during execution. Finally, 'isFinished ()' lets you see whether the asynchronous function has finished performing its operation. The last function returns true if one of the aforementioned 'isCompleted ()', 'isFailed ()', and 'isCancelled ()' is true.

The above-described interface was an interface for polling the execution state of an asynchronous function. However, status checking using only polling can waste unnecessary resources. Therefore, the progress status checker 112 according to the present invention additionally provides a status check method based on callback.

Reference numeral 104 in FIG. 3 represents an interface for setting a callback required to confirm the state transition of the asynchronous function. That is, start and stop listener configuration methods of asynchronous operation execution.

The 'setStartListener ()' method sets the callback to be called if the called asynchronous function is actually started. The interface of the callback to be called is described at 105. The 'setCompletionListener ()' method sets the callback to be called when the called asynchronous function terminates. The interface of the callback to be called is described at 106.

Another way to check the operation performance of a called asynchronous function is to wait for the called function to transition to its main state.

Reference numeral 103 denotes an interface that waits for the called function to actually start or end. Each provides two types: methods that wait indefinitely and methods that wait only a predetermined amount of time.

The call result obtaining unit 114 provides an interface for obtaining a call result value of the called asynchronous function. Here, since the call result obtaining unit 114 may obtain a result value only after the operation of the asynchronous function is completed, the call result obtaining unit 114 obtains the call result value of the called asynchronous function. Wait until the asynchronous operation finishes and get the result.

Reference numeral 102 in FIG. 3 represents an interface for obtaining a call result value of a called asynchronous function. Each function described by reference numeral 102 waits until the operation is completed if the operation is not finished, and returns a result value immediately if the operation is already completed. If an error occurs during the operation of the calling asynchronous function, it can be checked by generating an 'ExecutionException'. If it is forcibly canceled, it can be checked by generating a 'CancellationException'.

The exception processing unit 116 provides an interface for grasping error information generated while performing an operation of the asynchronous function called. That is, the function that can know the cause of the exception and the error that occurred during the execution of asynchronous operation through the 'ExecutionException' exception that occurs when calling a method described in the interface of the present invention and 'isFailed ()' described in 101. To provide.

The forced cancellation processing unit 118 provides an interface for forcibly canceling the called asynchronous operation execution function. The forced cancellation processing unit 118 may force the cancellation through the 'cancel ()' method as described with reference numeral 107 of FIG. 3.

The forced cancel processing unit 118 allows forcibly canceling the called asynchronous operation performing function even if not the caller of the original asynchronous function. The forced cancellation processing unit 118 may receive a cancellation reason for forcibly canceling the called asynchronous operation execution function as a string. In this case, when the forced cancellation processing unit 118 delivers an exception to the caller as an exception, the forced cancellation processing unit 118 transmits the cancellation reason together so that the caller can grasp the reason why the called function is canceled.

4 is a flowchart illustrating an asynchronous function call method for controlling a robot according to the present invention, and FIG. 5 is a diagram illustrating a driving interface for controlling robot driving using the asynchronous function call interface described above.

First, an asynchronous function for controlling a mechanical device (for example, a robot) is called by the caller, and thus a request for performing asynchronous operation is performed (S10 and S20). Unlike the synchronous function call, the called asynchronous function does not wait for the result value of the function to be calculated and returned after the function call. In operation S30, a control object for checking or controlling an asynchronous operation execution state of the corresponding asynchronous function is returned. At this time, the called asynchronous function follows a state transition as shown in FIG. In other words, if an asynchronous function is called but there are threads using the same resource, the asynchronous operation cannot be performed according to the asynchronous function call. Of course, whether or not to wait for a function can vary depending on the scheduler. When all the threads that are ahead of the thread have finished using the resource, the called function is allocated the resource and transitions to the actual asynchronous operation. However, in the case of controlling a mechanical device such as a robot, asynchronous operation execution cannot be completed successfully due to frequent errors in this operation state (i.e., 'RUNNING' state) and failed state (i.e., 'FAILED' state). Is often transitioned to).

Therefore, in the present invention, the control object capable of controlling the asynchronous operation execution state is returned in step S30, and the status of the asynchronous operation execution according to the asynchronous function call can be checked through the returned control object (S40). That is, check the status of asynchronous operation execution according to asynchronous function call through control object. In this case, an object of type 'AsyncOperation' defined in FIG. 3 may be used as a control object for controlling the execution state of the asynchronous function called in step S40.

Next, in step S40, the asynchronous operation execution state is checked, and the result is determined whether the asynchronous operation execution state is in a state in which cancellation is possible (S50).

If the cancellation is possible, it is determined whether a forced cancellation request is received (S60). If a forced cancellation request is received, the cancellation process is input as a string from the rigid cancellation requester (S90). Then, the caller is sent as an exception with the cancellation reason (S100).

On the other hand, step S50 and step S60 may be performed in a different order. That is, first, it may be determined whether a forced cancellation request is received, and when the forced cancellation request is received, it may be determined whether the execution state of the currently called asynchronous function is cancelable.

When the forced cancellation request is not received in step S60, the asynchronous operation result value of the asynchronous function called through the control object is obtained and provided to the caller (S70). In this case, the result value of the asynchronous operation execution can be obtained only when the asynchronous operation ends. Therefore, to obtain the result value of the asynchronous operation execution, it waits until the operation execution of the asynchronous function ends and then obtains the result value. do. Reference numeral 102 in FIG. 3 represents a control object for obtaining a call result value of the called asynchronous function. Each function described in the reference numeral 102 waits until the operation is completed if the operation is not finished, and provides a result value immediately if the operation is already completed.

Next, the cause of the error occurred while performing the operation of the asynchronous function called is provided to the caller (S80). That is, through the 'ExecutionException' and 'isFailed ()' described in FIG. 3, the cause of the exception and the error occurring during the asynchronous operation are identified and provided to the caller.

For example, FIG. 5 shows a function 'navigateToLandmark ()' that drives a mechanical device such as a robot to a predetermined landmark. When this function is called, it does not wait for the actual driving to complete but rather executes the driving request asynchronously and transfers control directly to the caller. That is, an object of type 'AsyncOperation' defined in FIG. 3 is returned as an object for querying or controlling the state of the called driving function. The driving function caller can control the driving operation at any time through the 'AsyncOperation' object received after the function call.

6 shows an example of calling a driving function.

In FIG. 6, the robot requests driving in a 'room' (401). Then, the vehicle waits for a maximum of 30 seconds to complete (402). If the driving is not completed before 30 seconds, a 'TimeoutException' is generated, thereby forcibly canceling the requested driving (403).

According to the present invention, the asynchronous function caller can control the execution of the asynchronous operation at any time through the control object returned after the function call, and the asynchronous function call like applications that control a mechanical device such as a robot through a computer program. This frequently used application can facilitate the developer's work, which is effective.

On the other hand, asynchronous operation is not only a control to a mechanical device such as a robot, but also variously occurs in other IT fields, and the field of application of the present invention described above is just one embodiment. In addition, the asynchronous operation interface based on the Java language is also a way to describe the concept, it is possible to extend the concept by implementing it through various programming languages.

The present invention can be embodied as computer-readable codes on a computer-readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media may include ROM, RAM, CD-ROM, magnetic tape, floppy disk, and optical data storage. Also included are those implemented in the form of carrier waves (eg, transmission over the Internet). The computer readable recording medium can also be distributed over network coupled systems so that the computer readable code is stored and executed in a distributed fashion.

As described above, the best embodiment has been disclosed in the drawings and the specification. Although specific terms have been used herein, they are used only for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the meaning or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a diagram for explaining a state transition of called asynchronous functions.

2 is a view for explaining the structure of an asynchronous operation layer in the asynchronous function call system according to the present invention.

3 illustrates an interface of an object for controlling asynchronous function calls implemented using the Java language.

4 is a flowchart illustrating a asynchronous function call method for robot control according to the present invention.

5 is a diagram illustrating a driving interface for controlling robot driving using the asynchronous function call interface described above.

6 is a diagram illustrating an example of calling a driving function.

Claims (8)

In the asynchronous function call method for controlling a mechanical device, Receiving a request to perform an asynchronous operation according to an asynchronous function call; Immediately returning a result according to the asynchronous operation execution request and returning a control object capable of controlling the asynchronous operation of the asynchronous function; Whether the asynchronous function called by the returned control object has started, whether the called asynchronous function has completed successfully, whether the called asynchronous function was interrupted due to an error while executing, or the calling asynchronous function was forced during execution. Checking whether the asynchronous operation execution state is a cancelable state by checking at least one of whether the operation is canceled and whether the called asynchronous function has finished performing the operation; If the asynchronous operation execution state is a cancelable state, confirming whether a forced cancellation request is received; And If the force cancellation request is received, forcibly canceling the asynchronous operation. The method according to claim 1, And if a force cancellation request is not received, acquiring a result value of performing the asynchronous operation through the returned control object and providing the result to the caller. The method according to claim 2, And determining a cause of an error occurring during the asynchronous operation by using a result value of the asynchronous operation. The method according to claim 2, Acquiring the result of performing the asynchronous operation, If the asynchronous operation is not finished, the method waits until the end of the asynchronous operation is completed, the asynchronous function call method, characterized in that to obtain a result value of the asynchronous operation. The method according to claim 1, The step of checking whether the asynchronous operation execution state is a cancelable state, And checking whether the asynchronous operation execution state is a cancelable state by a polling method through the returned control object. delete The method according to claim 1, The step of checking whether the asynchronous operation execution state is a cancelable state, And checking whether the state of performing the asynchronous operation is cancelable by a callback method through the returned control object. The method according to claim 1, When the forced cancellation request is received, forcibly canceling the asynchronous operation is performed. A method of calling an asynchronous function characterized in that the cancellation processing is performed by receiving a cancellation reason as a string from the forced cancellation requestor requesting the forced cancellation.

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