KR20130017698A - Realtime robot control framework - Google Patents

Abstract

PURPOSE: A real time robot control framework is provided to easily develop/test robot control algorithm by controlling a real robot in real time based on the integration of a commercial RTOS(Real-Time OS) with a software framework. CONSTITUTION: An RTOS device plug-in(414) is paired with a Windows device plug-in(406) and connected with a robot device. A shared memory(420) inputs and outputs data of the RTOS device plug-in and the Windows device plug-in. An RTOS process(412) controls the RTOS device plug-in, the shared memory, and a robot system registered in an RTOS timer using the RTOS timer provided from a commercial RTOS in order to apply robot control algorithm to the robot device in real time. [Reference numerals] (402) Window process; (404) Control plug-in; (406) Window device plug-in; (412) RTSS process; (414) RTSS device plug-in; (416) Device driver; (418) Robot device; (420) Shared memory

Description

Real Time Robot Control Framework {REALTIME ROBOT CONTROL FRAMEWORK}

The present invention relates to a robot real-time control framework, and more particularly, a robot real-time control frame that supports a software framework that allows users to control a real robot in real time by integrating a real-time operating system into the framework of the robot control software. It is about a work.

Robots are classified into various types, but typical ones are mobile robots that are equipped with wheels or moving means to carry out simple tasks such as carrying or cleaning objects, and moving parts or welding by moving one or more arms (arms). There are industrial robots, humanoid robots that can be configured similar to the structure of the human body and can behave similar to human behavior.

In addition, a dog-type robot, which consists of four legs such as dogs and horses, carries a four-legged walk and performs cargo transportation, combat, and life-saving work, and the present invention refers to such a mobile robot, industrial robot, and humanoid robot. It is used to mean robots and dog-like robots.

In order to develop a robot, the hardware constituting the robot and the software for controlling the robot must be implemented at the same time. When there is an error in the software for controlling the robot implemented in hardware or does not match the structure of the actual hardware, the hardware or software Should be redesigned.

However, even a simple robot is made up of many motors, sensors, joints, computers, etc., and thus, changing components again in the state of completion of production can cause a great loss in time and cost. In addition, before completing the robot, it is impossible to know exactly what is wrong with the operation or structure of the robot, so it was possible to produce an accurate robot only after several trials and errors.

In order to eliminate such inconvenience, tools are disclosed that can produce a virtual robot in software and simulate it in three dimensions before producing the actual robot and compare it with the actual motion. These simulation tools store control algorithms designed by researchers designing robots and virtually operate them in software according to the stored algorithms to determine if there are any problems.

1 is a flow chart showing a development process of a conventional robot system, as shown in FIG. 1, the development process of a robot system is generally a mechanical design and assembly, electronics integration, control algorithm development, control algorithm embedded and system It can be summarized as a process of integration.

The instrument design and assembly process includes detailed processes such as instrument mechanism design, workspace analysis, driving force analysis, actuator and sensor selection. In the electronic integration process, the design and implementation of the control board, the device driver, and the like are implemented and integrated with the apparatus. In the development of control algorithm, control structure design, real-time control kernel implementation and control protocol implementation are performed.

Finally, in the embedding of control algorithms and system integration, the robot system is completed by integrating and testing the components developed at the previous stage.

After completing the design of the robot as described above, the real-time control algorithm is mounted on the assembled robot before assembling the actual robot and embedding the control algorithm as designed. This is done by implementing an algorithm controller to verify the performance of the assembled robot in real time.

The conventional real time control application does not operate in the same framework as the robot control software, so the control algorithm plug-in developed in the robot control software cannot be reused as it is in the real time control application. Therefore, since different control algorithm plug-in interfaces are used, it is inconvenient to perform additional operations such as reprogramming or recompiling the control plug-in verified in the simulation.

Korea Patent Registration 10-0756345 ("Robot Simulation System Using Network", Simulation Research Institute, 2007. 09. 10 published)

It is a first object of the present invention to provide a real time robot control framework for allowing software framework users to perform real time control on a real robot with a robot control algorithm developed and validated in the software framework.

In addition, the second object of the present invention is to implement a real-time control application program using a commercial real-time operating system to write a real-time robot control program as a general software framework application program using a user application programming interface (API) To provide a robot control framework.

The real-time robot control framework according to an embodiment of the present invention is linked with a software framework including a window process, a control plug-in for inputting and outputting a robot control algorithm to the window process, and a window device plug-in connected to the window process. A robot control framework for controlling a robot device in real time on a device, comprising: an RTSS device plug-in coupled to the window device plug-in and connected to the robot device; A shared memory configured to allow the window device plug-in and the RTSS device plug-in to input and output data; And controlling the robot system registered in the RTSS device plug-in, the shared memory, and the RTSS timer at a predetermined time period by using the RTSS timer provided by the commercial real-time operating system to apply the robot control algorithm to the robot device in real time. It may include an RTSS process.

The RTSS process may synchronize the window device plug-in and the RTSS device plug-in.

When the timer event occurs in the RTSS process, the RTSS process reads the device value from the sensor of the robot device and writes it to the shared memory, and after the window process reads the device value from the shared memory, executes the control algorithm. The control input of the robot device is calculated and the calculated control input is written to the shared memory, and the RTSS process sequentially applies the control input stored in the shared memory to the robot device. The reading of the device value may execute a read mode in which the RTSS timer is executed at regular intervals.

When a timer event occurs in the RTSS process, the RTSS process applies a control input of the robot device stored in the shared memory to the robot device, reads a device value from a sensor of the robot device, and writes it to the shared memory, and the window process The controller may sequentially execute an operation of calculating the control input by executing the control algorithm, and execute a write mode in which the operation of applying the control input to the robot device is performed at a predetermined cycle by the RTSS timer.

The RTSS process may select and execute any one of the read mode and the write mode.

According to the real-time robot control framework of the present invention, since the real-time robot can be controlled in real time by integrating a commercial real-time operating system into the software framework, there is an effect that allows users to develop and easily test the robot control algorithm.

Also, since the code is almost similar to the simulation code of the software framework, the application code verified in the simulation environment can be reused with a few modifications.

According to the real-time robot control framework of the present invention, since the control algorithm plug-in developed in the software framework can be reused as it is in the real-time robot control framework application, the control plug-in verified in the simulation is reprogrammed or recompiled, etc. It can be applied to real time control without additional work.

Moreover, since it includes RTX Runtime, which is a Windows-based commercial real-time operating system, it is possible to reduce additional costs including the huge cost of purchasing the RTX SDK.

1 is a flow chart showing a development process of a conventional robot system,
2 is a view for explaining a real-time robot control framework according to an embodiment of the present invention,
3 is a view for explaining the structure of a real-time robot control framework according to an embodiment of the present invention;
4 is a block diagram schematically illustrating a real-time robot control framework according to an embodiment of the present invention;
5 is a view for explaining a read mode of the real-time robot control framework according to an embodiment of the present invention;
6 is a view for explaining a write mode of the real-time robot control framework according to another embodiment of the present invention;
7 is a block diagram illustrating a case where a real-time robot control framework uses an RTAPI timer according to another embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.

It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted in an ideal or overly formal sense unless explicitly defined in the present application Do not.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention. In order to facilitate the understanding of the present invention, the same reference numerals are used for the same constituent elements in the drawings and redundant explanations for the same constituent elements are omitted.

2 is a view for explaining a real-time robot control framework according to an embodiment of the present invention. As shown in FIG. 2, a robot control algorithm is developed in an algorithm framework (not shown) to verify performance in the software framework 200. The verified robot control algorithm is connected through a network with a simulation terminal 202 in charge of a real robot 220 or a virtual robot simulation to control motion through the real-time robot control framework 210.

The algorithm framework (not shown), the software framework 1200, and the real-time robot control framework 210 may be composed of separate hardware, but it will be more common to implement software in one server system. Therefore, each component of the present invention may be understood as a collection of software that performs the function pursued by each component, and the algorithm used in the present invention may be understood as a storage device that stores data for performing the algorithm. There will be.

The main object of the entire robot system of the present invention is to enable the rapid development of algorithms for robot control, and the hardware (actual robot 220) without changing the robot algorithm and development framework developed by software. Is to make it applicable.

An algorithm framework (not shown) is a part for generating and storing a control algorithm for manipulating the motion of the robotic system. The software framework 200 provides a service environment that is communicated with a unified programming and debugging environment. For this purpose, an abstraction of robot hardware, an abstraction of a sensor and a driving device, an algorithm abstraction, a component abstraction, and real-time control are required. Control algorithms implemented on the software framework can be reused for simulation and control of the actual robot 220.

Approaches to satisfy the efficiency and real-time controllability of resource usage of the software framework 200 are modularization and decentralization. You can modularize robots, sensors and drives, algorithms, and components, and define interfaces that abstract data input and output for each module. Execution modules that implement this abstraction interface can run together in the same process or can be distributed across a network.

In addition, since the actual implementation exists inside the module, it can be changed to a simulation module, a robot hardware control module, and a real-time control module that implement the same interface as needed. Each module runs in an independent thread, process, or system, optimizing performance on multi-core processors.

According to the above method, the software framework 200 controls the operation of the real robot 220 or the virtual robot through the robot control algorithm input from an algorithm framework (not shown) through the real-time robot control framework 210, Provides a path for conversion and transmission of control signals.

The real-time robot control framework 210 according to the present invention, as described above, can be applied to the robot hardware 220 of various forms as it is, without a separate change operation, the robot control algorithm verified by the software framework 200. Provide an environment for doing so.

3 is a view for explaining the structure of the real-time robot control framework according to an embodiment of the present invention. As shown in FIG. 3, the real-time robot control framework according to the present invention allows the application of the software framework to use a hard realtime timer provided by RTX, a real-time extension module of Windows. It serves as an interface to extend functionality. In other words, when a user uses an application, the software framework provides an interface that enables real-time robot hardware to be operated in real time based on the RTX of Window, which is a commercial real-time operating system (RTOS), or the RTAI of Linux.

RTX is a module that extends the MS Windows operating system to take advantage of real-time timers, and RTAI is a module that extends the Linux operating system. When the function is extended to the commercial real-time operating system, the real-time robot control framework provides an API so that the user can easily utilize the functions of the commercial real-time operating system, and the important point here is in the robot control algorithm or robot operation program that the user writes. There is no need to deal directly with a commercial real-time operating system. In addition, as described above, the real-time robot control algorithm is an interface that extends the functionality of the software framework. Therefore, robot models, control algorithms, devices, and various plug-ins developed using the software framework can be used through the real-time robot control framework.

4 is a block diagram schematically illustrating a real-time robot control framework according to an embodiment of the present invention. The real time robot control framework 410 according to the present invention uses a real time timer (not shown) of an extension module (RTX) of a commercial real time operating system (RTOS). Real-time timers include RTAPI timers and RTSS timers. The RTAPI timer does not use the RTSS process 412. It is easier to use than RTSS timer, so it is used in the development and debugging stage of real time control algorithm. The RTSS timer can be used when an accurate real-time timer is required compared to the RTAPI timer. Thus, the real time robot control framework 410 uses the RTSS process 412. Since RTAPI timers are used in extremely exceptional cases, we will focus on RTSS timers. The RTSS timer generates a timer event at a set timer time period. 1000 cycles per second (1khz) is a common timer cycle.

As shown in FIG. 4, the real-time robot control framework 410 according to the present invention includes an RTSS process 412, an RTSS device plug-in 414, and a shared memory 420. The software framework 400 has a structure in which various plug-ins 410 and 406 operate by exchanging data with each other.

The window process 402 performs a function of controlling the control plug-in 404 and the window device plug-in 406. The window process 402 can utilize a shared memory 420 that can share data with the RTSS process 412. In addition, a specific function of the control plug-in 404 may be called to execute a logit control algorithm written by a user, and the control input value may be calculated. The window process 402 may control data input and output with the actual robot device 418 through the window device plug-in 406.

The control plug-in 404 is a component that inputs the robot control algorithm developed in an algorithm framework (not shown) to the window process 402. The control plug-in 404 may receive a control command of the window process 402 to exchange data with a device according to a standard device interface standard. Therefore, it is not necessary to know exactly which device each device is. For example, the virtual device for simulation (not shown) and the actual robot hardware device 418 can be accessed in the same manner. Thus, when the virtual robot device (not shown) and the real robot device 418 are modeled as devices having the same device specification, the virtual robot device (not shown) and the real robot device 418 are the same with the same control plug-in 404. Can be controlled.

The window device plug-in 406 receives a command of the window process 402 to perform input / output of data to be transmitted to the actual robot device 418. That is, when transmitting from the software framework 400 to the actual robot device 418, the data is written to the shared memory 420 through the window device plug-in 406, and the RTSS device plug-in (412) is received by the RTSS process 412. In 414, data is read from the shared memory 420 and transmitted to the robot device 418.

The real-time robot control framework 410, which transmits data in real time to the real robot device 418 in conjunction with the software framework 400 operating in the above manner, includes an RTSS process 412, an RTSS device plug-in 414, and The shared memory 420 is included.

The RTSS process 412 controls the RTSS device plug-in 414 and the shared memory 420 to apply a robot control algorithm developed by a user to the real robot device 418 in real time. The RTSS process 412 synchronizes the control algorithms executed in the window process 402 and executes them in real time. Additionally, data synchronization is performed between the Windows device plug-in 406 and the RTSS device plug-in 414. Since the real-time robot control framework 410 is pre-implemented to perform such a task, the user may implement a real-time control application without any programming work associated with an extension module (RTX) of a commercial real-time operating system.

The RTSS process 412 controls a robot control system and a robot controller registered to the RTSS timer at a predetermined time period using an RTSS timer (not shown) provided by a commercial real-time operating system and controls input / output of data.

The RTSS device plug-in 414 may be paired with the window device plug-in 406 to receive data from the RTSS process control command, input / output data to the shared memory 420, and transmit data to the robot device 418. In addition, data synchronization with the Windows device plug-in 406 occurs according to the instructions of the RTSS process 412. In order to control the real robot device 418, a control algorithm and hardware interface programming between the real robot system must be performed. The real-time robot control framework 410 of the present invention is a CAN, IEEE 1394, and EtherCAT communication device and multiple ISAs. In addition, the RTSS device plug-in 414 is provided for PCI bus-based DAQ boards, so it is easy to integrate with the hardware system employing the above devices.

The device driver 416 functions as a transmission path between the robotic device 418 and the RTSS device plug-in 414. Since the RTSS device plug-in may include one or more robot devices 418, each robot device 418 may recognize the robot device 418 through the device driver 416.

The robotic device 418 is controlled in real time via the real time robot control framework 410 according to a control algorithm called through the control plug-in 404.

When a real-time timer event occurs according to an embodiment of the present invention, look at the data flow of the controller using a sensor and a motor, which is one of the robot devices 418. The real-time robot control framework 410 automatically handles the following tasks.

First, when a real time timer event occurs, the RTSS process 412 reads the sensor of the particular robotic device 418 and writes the device value to the shared memory 420. The window process 402 reads the value from the shared memory 420 to update the encoder device buffer (not shown) of the window area. The window process 402 then executes the user-written robot control algorithm by calling the update function using the control plug-in 404. The control algorithm calculates the control inputs and writes the calculated control inputs to the device buffer (not shown) of the motor device. Next, the window process 402 copies and writes the buffer value from the device buffer (not shown) of the motor device to the shared memory 420. The RTSS process 412 completes the operation by reading the control value of the shared memory 420 and applying it to the actual motor.

5 is a view for explaining a read mode of the real-time robot control framework according to an embodiment of the present invention. When using the RTSS timer, the RTSS process can select the I / O mode as either read mode or write mode. First, the read mode is selected.

When timer event occurs in RTSS process, device value is read from sensor such as encoder. The shared algorithm then executes the control algorithm through a control plug-in in the Windows process. The control algorithm calculates control inputs such as rotational torque. The calculated control inputs are written to shared memory and the RTSS process applies them to devices such as real motors via RTSS device plug-ins. At this time, the operation of reading the device value from the sensor is called by synchronizing at the correct period by the RTSS timer (Synchronous Read). As can be seen from FIG. 5, the process of the read mode is completed within one cycle of the RTSS timer.

6 is a view for explaining a write mode of a real-time robot control framework according to another embodiment of the present invention. That is, the case where the RTSS process selects the write mode as the input / output mode will be described.

When a timer event occurs in the RTSS process, the RTSS process applies previously calculated control inputs to devices such as motors. Then, the device value is read from a sensor such as an encoder. When the RTSS process stores the device value in shared memory, the window process reads the value and executes the control algorithm through the control plug-in to calculate the control input such as torque. After that, the calculated control input is written to the shared memory, and the RTSS process applies it to a device such as a real motor through the RTSS device plug-in. At this time, the operation of applying the device value to the motor is called by synchronizing at the correct period by the RTSS timer (Synchronous Write). As can be seen from FIG. 6, the above write mode process uses a value calculated in a previous cycle of the device value applied to the motor, so that a delay of up to one cycle (cycle of the timer) may occur.

7 is a block diagram illustrating a case in which the real-time robot control framework uses an RTAPI timer according to another embodiment of the present invention. As described above, the RTAPI timer is often used in the development and debugging stage of the real-time control algorithm. This is because it is simpler to use than the RTSS timer. Applications that use the RTAPI timer do not use the RTSS process. Thus, data input and output with the actual device occurs directly in the window process 702 and the window device plug-in 706.

When a timer event occurs, the window process 702 updates the sensor of the robot device 710 with an encoder device buffer (not shown) in the window area. The window process 702 then executes a user-written robot control algorithm by calling the update function using the control plug-in 704. The control algorithm calculates the control inputs and writes the calculated control inputs to the device buffer (not shown) of the motor device. Next, window process 702 completes the operation by reading the buffer value from the device buffer (not shown) of the motor device and applying it to the actual motor. As described above, since the actual robot device 710 is controlled in accordance with an accurate period, it is meant to be controlled in real time. Therefore, an RTAPI timer having low accuracy is generally not used.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions as defined by the following claims It will be understood that various modifications and changes may be made thereto without departing from the spirit and scope of the invention.

200: software framework 202: simulation terminal
210: real-time robot control framework 220: real robot device
400: Software Framework 402: Windows Process
404: Control plug-in 406: Windows device plug-in
410: real-time robot control framework
412: RTSS process 414: RTSS device plug-in
416: device driver 418: robot device
420: shared memory
702: Windows Process 704: Control Plug-in
706: Windows Device Plug-in 708: Device Driver
710: robotic device

Claims (5)

A robot control frame that controls a robot device in real time on a real-time operating system (RTOS) in conjunction with a software framework including a window process, a control plug-in for inputting and outputting a robot control algorithm to the window process, and a window device plug-in connected to the window process. In the work piece,
An RTSS device plug-in paired with the window device plug-in and connected to the robot device;
A shared memory configured to allow the window device plug-in and the RTSS device plug-in to input and output data; And
RTSS for controlling the robot system registered in the RTSS device plug-in, the shared memory and the RTSS timer at regular time intervals by using the RTSS timer provided by the commercial real-time operating system to apply the robot control algorithm to the robot device in real time. Real-time robot control framework comprising a process.
The method of claim 1,
The RTSS process synchronizes the window device plug-in with the RTSS device plug-in.
The method of claim 1, wherein when a timer event occurs in the RTSS process,
The RTSS process reads the device value from the sensor of the robot device and writes it to the shared memory,
After the window process reads the device value from the shared memory, executes the control algorithm to calculate the control input of the robot device and write the calculated control input to the shared memory,
The RTSS process sequentially applies the control input stored in the shared memory to the robot device,
And a read mode in which the reading of the device value by the sensor is performed at a predetermined cycle by the RTSS timer.
The method of claim 1, wherein when a timer event occurs in the RTSS process,
The RTSS process applies a control input of the robot device stored in the shared memory to the robot device, and then reads a device value from a sensor of the robot device and writes it to the shared memory,
The window process executes the control algorithm and sequentially calculates the control input,
And executing the write mode in which the applying of the control input to the robot device is performed at regular intervals by the RTSS timer.
The method according to claim 3 and 4,
And the RTSS process selects and executes either the read mode or the write mode.

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