KR20080038865A - Mobile manipulator system based on configuration control of mobile robot and task robot - Google Patents

Abstract

A mobile autonomic system based on cooperation control of a movable robot and a task robot is provided to improve the independency and processing speed of each controller through a CAN(Controller Area Network) control scheme, and to expand functions of the mobile autonomic system. A mobile autonomic system based on cooperation control of a movable robot and a task robot comprises an upper controller having a main controller connected with an active camera. A task robot is connected with the main controller and controlled by a six-axis motor controller. Lower controllers are connected with the main controller. The lower controller includes a CAN controller for network control of three motor controllers for 3-axis control of a movable robot and one motor controller for Pan/Tilt control of the active camera. The main controller obtains image and robot status information, processes an image, designs a robot operation, and transmits a command to the lower controller.

Description

MOBILE MANIPULATOR SYSTEM BASED ON CONFIGURATION CONTROL OF MOBILE ROBOT AND TASK ROBOT}

1 is a specific example of a mobile autonomous robot system based on the cooperative control of a mobile robot and a working robot of the present invention.

2 is a system configuration diagram of a mobile autonomous robot system of the present invention.

3 is a simulation test result of the active camera of the present invention.

4 is a path generation algorithm (using the line correspondence relationship between the object and the image of the actual target point by the position information of the target target point and the image processing of the camera).

5 shows a simulation result approaching the target position in three dimensions by the mobile autonomous robot system of the present invention.

6A, 6B, 6C, 6D, 6E, and 6F are photographs of simulation results confirming that a specific work of the work robot is smoothly performed.

The present invention relates to a mobile autonomous robot system based on cooperative control of a mobile robot and a work robot. The present invention relates to a mobile autonomous robot system configured to perform a desired task by cooperative control of a mobile robot and a work robot.

According to the analysis of the cause of accidents in stages of construction work surveyed in the last two years in Korea, the percentage of accidents that occurred at construction sites was 78% of total work, rather than indoor work such as planning and design. It is said to occupy.

In particular, when considering the causes of construction stage accidents, human error is related to more than 95% of the causes of accidents, except for about 2.5% of external environmental causes, such as personal carelessness, work supervision error, prior consultation error, equipment handling error, and inspection error. Able to know.

Therefore, it can be said that at least 70% or more of all construction accidents can be largely solved by strengthening the safety system, including "mechanization, automation, and robotization of construction sites."

As the development of technology and the automation of many tasks in the industrial field are automated, the role of robots becomes increasingly important.

In particular, since the mid-twentieth century, the industry has developed rapidly, and now the robot has started to be carried out by robots, even from the use of robots for simple tasks, to tasks that are difficult for humans to work. There is a need for supervisory control, which consists of automating knowledge information.

For such supervisory control, technologies for acquiring and communicating information about the actual working environment and the development of information communication technology with the working environment at a remote location and realizing the real environment through communication are realized.

In particular, special bridge structures, such as cable-stayed bridges, are subject to plastic deformation in the structure when displacements exceed the allowable values or excessive external forces when displacement occurs vertically or horizontally depending on external forces such as load or seismic force. Displacements and deformations caused by ground subsidence, movement, and reduced bearing capacity impede the stability of the structure.

When harmful displacement, deformation, corrosion and cracking occur in such a structure, appropriate measures are necessary because the structure may have insufficient rigidity or strength, excessive stress may occur in the member, and the structure may become unstable.

However, the measurement of damage caused by deformation and cracking and corrosion of these special bridge structures is in a difficult state to accurately measure due to environmental factors.

In addition, the deterioration of the special bridge structure with time must be monitored at all times, and appropriate response to changes in the situation is required. Therefore, it is suitable as a general industrial robot that performs repetitive work according to a predetermined program in a static work environment. Since there is a problem that can not be performed easily, it was required to develop an intelligent maintenance robot that can actively respond to changes in the situation.

In addition, when the distance between the operator and the robot is far, such as a robot used for space exploration, even if the information on the working environment is obtained using the information of the images and sensors, there is a problem due to time delay in delivering the information to the operator. do. In addition, there is a problem according to the accuracy of the image and sensor in obtaining the work environment information.

As such, research and development of a sensor fusion technique including an image and a laser has been required to solve the problems caused by the limitations of accuracy and information acquisition of individual sensors and the problems caused by time delay.

In addition, research has been required for the development and implementation of algorithms for real-time control of communication technology and robots so that the real-time remote control system is precisely realized by the efficient use of data by such sensors.

The present invention is to solve the above technical problem, an object of the present invention is to measure in real time damage information, such as deterioration of structures that are difficult to access, such as special bridge structure in real time, the damage information to a remote worker in real time In order to provide a mobile autonomous robot system based on cooperative control of a mobile robot and a work robot capable of actually maintaining a structure according to a worker's command.

The mobile autonomous robot system proposed in the present invention is provided in a form based on cooperative control of a mobile robot and a work robot (mobile manipulator).

In other words, the robot based on the cooperative control according to the present invention is a combination of a mobile robot and a work robot. The mobile robot is a non-holonomic system, and the work robot is a holonomic system. Therefore, the kinematics of the mobile robot and the work robot move through the speed kinematics. Combine robot and work robot.

In addition, in order to precisely control mobile robots and work robots and related tasks in real time through the camera and other sensors to identify the damage information of the structure in real time, the present invention provides a plurality of controllers through the network Adopt the distributed control method.

In the mobile autonomous robot system of the present invention, a CAN (Controller Area Network) control method is introduced so that the main controller issues commands to the lower controller through the network, and the lower controller performs distributed control on a given posture and speed command. . The CAN control method increases the independence and processing speed of each controller and makes it easy to expand the functions of the mobile autonomous robot system.

Also, in order to recognize the target point at an arbitrary position, the spatial position of the target point is obtained by using the image data inputted by the two degree of freedom active camera attached to the top of the robot and the kinematic relationship of the active camera. .

In addition, at the same time as the location is reached, the road map can be created and the status of the structure can be checked through the image information of the camera so that the image data and other situation data can be transmitted to the worker.

In this transmission process, precise RF design technology considering environmental impact (vibration and noise) is provided. Through this, the work robot (manipulator) may have a work schedule for performing maintenance work based on the recognized information.

In addition, due to the nonuniformity of the moving surface of the mobile robot, the information of the position sensor attached to the rail is inaccurate to provide the position and direction of the robot. Therefore, even if the proper work is assigned to the mobile robot, it is difficult to expect precise control.

Accordingly, the mobile robot of the present invention recognizes the location information of the mobile robot by utilizing the line correspondence between the object and the image of the actual target location by the image processing of the camera and the target target location. By using the position information and the position obtained from the position sensor attached to the rail together, it is possible to realize the precise control of the mobile robot to recognize the position of the mobile robot and use it for control.

   The mobile autonomous robot system according to the present invention, for example, to measure the corrosion and cracks for the maintenance of special bridge structures, and to provide a method for transmitting them to the worker in real time, and to repaint and crack repair of the corrosion-deteriorated member, etc. Maintenance work is possible.

BRIEF DESCRIPTION OF DRAWINGS To describe the present invention more clearly and easily, the following describes the best embodiments of the present invention in detail with reference to the accompanying drawings, and embodiments according to the present invention may be modified in various other forms, and thus the scope of the present invention. Is not limited to the embodiment described below.

<Mobile autonomous robot system based on cooperative control of mobile robot and work robot>

As the use range of robots is diversified, efficient utilization using robots is expected in the present industry. However, in reality, the use of robots has not been revived with great expectations in terms of the utilization of robots because there is a lot of uncertainty when controlling robots in a real environment, and even in the case of working robots with six degrees of freedom or less When viewed from the attitude side of the robot, there is a problem that it is difficult to perform efficient work low stability.

Accordingly, the interest in multiple robots has increased so that a plurality of robots can perform work by mutual cooperation, and the interest in increasing the stability and efficiency of the working point is increasing.

The present invention enables to perform the necessary work by such a multi-robot, which is embodied by a mobile autonomous robot system having a surplus induction by a series combination of a mobile robot and a working robot.

The mobile robot cannot work, and the work robot has a limited working space and needs sensor information for perception to perform tasks while intelligently coping with an uncertain environment.

In order to overcome these limitations, the present invention uses a camera to reach an unknown workspace, constructs a mobile autonomous robot system for realizing cooperative control by combining a mobile robot and a work robot having independent work performance in series. It can be done smoothly and mutually.

However, it is different from the method of using surplus degree of freedom of working robot with fixed freedom and surplus freedom generated by the combination of mobile robot and working robot. It is necessary to study the trajectory planning of the mobile autonomous robot system considering the surplus degree of freedom problem caused by the serial combination of mobile robot and working robot.

The mobile autonomous robot system proposed by the present invention is composed of a work robot for directly performing a work as shown in FIG. 1 and a mobile robot for extending a work range. In order to be able to recognize, the camera with the active structure of Pan / Tilt 2-freedom is included.

In order to recognize the object at an arbitrary position, the spatial position of the object is obtained by using the image data input by the active camera of 2 degrees of freedom attached to the working robot and the kinematic relationship of the active camera. Create an optimal path for the robot to do its job.

In order to verify the efficiency of the robot's control structure and path planning algorithm, the robot recognizes objects at arbitrary locations and captures them and analyzes the results.

As a result, it was found that the robot can perform the work smoothly even for work outside the work area through the optimum path and cooperation of the robot.

In addition, it can be seen that the introduction of the distributed control method using the CAN method can efficiently perform many control tasks required for the mobile robot operation in real time.

Figure 2 shows the overall system configuration of the mobile autonomous robot system.

There are six controllers in total and they are divided into one upper controller and five lower controllers.

The host controller uses a PC to which the USB-TO-PCI card for image information is interfaced via the PCI bus, and the four CAN controller cards for the 3 axis of the mobile robot and the Pan / Tilt controller network of the active camera. And ISA interface card for CAN communication with the host controller (PC).

The 8051 controller for controlling the working robot is designed to serially communicate with the host controller.

The upper controller performs image acquisition and robot status information acquisition, image processing, robot operation planning, and command transmission processing to the lower controller at a cycle of 100 msec.

The controller of the active camera receives the posture command transmitted from the host controller through the parallel port of the ISA interface card.

Pan / Tilt of active camera is assigned with different ID from one controller to control each axis at the same time, and realized acceleration / deceleration function and holding function to realize high-speed precision control.

The lower controller module that controls the speed of each wheel of the mobile robot performs PID control with a control cycle of 10 msec to follow the speed command received from the upper controller through the network.

The PID controller is designed to be robust to the dynamics caused by robot motion.

The mechanical part of the active camera used in the present invention is configured to enable two degrees of pan / tilt operation using two joints. Step motor is used as driver of each joint and Pan / Tilt operation is controlled to 0.9 [deg / pulse].

Looking at the simulation and experiment by the mobile autonomous robot system as described above are as follows.

Simulations and experiments were performed to verify the validity of the distance estimation using the kinematic relationship between the image information and the camera.

Simulation shows the kinematic relationship presented in the present invention to the image of the bottom of the 1m grid according to the posture of the active camera. 3 shows the results of experiments in the posture of an active camera Tilt angle, α = 14.4 ^o , Pan angle, β = 24.3 ^o .

In FIG. 3, the front of the box in the corridor is placed at a certain distance from the center of the working robot according to a predetermined coordinate system, and then processed by actual input images and algorithms (target tracking and driving marker algorithms) in the active camera pose. It shows the video and its data.

As can be seen from the experiment, the distance information is estimated through the kinematic relationship with the image information by the actual camera posture.

In the mobile autonomous robot system, FIG. 4 illustrates a path generation algorithm (using the line correspondence relationship between the object and the image of the actual target point by the position information of the target target point and the image processing of the camera).

Before the simulation, the initial position and direction of the moving object were (0m, 0m, 0.55m, 0 ^o ), and the initial posture of the working robot was set to (-60 ^o , 20 ^o , -15 ^o ). The target position of the end-effector of the robot was set to (1m, 5m, 0.7m). Also, the average moving speed of the mobile robot was 2 m / s.

5 calculates an error with the target position starting from the initial position. The simulation results approaching the target position in three dimensions while driving the optimal path generated by the curvature S and the speed of the system parameters minimizing the price function L.

The final position from the simulation results is (0.9451m, -5.148m, 0.7m). The cause of the error is that the minimization process is based on an approximate method and appears to be due to the setting of threshold values for the minimum error.

6A illustrates an operation of finding a box at a target position, and FIGS. 6B to 6F illustrate an operation of dropping an object grasping onto a box at a target point. Experimental results confirm that the task robot finds the target position and drops the object to the target position. The position estimation using the information of the camera and the position of the mechanical part is performed, and the specific work of the robot is performed smoothly due to the optimal path. .

Use of the work robot of the present invention is advantageous for work existing outside the current work space as compared to the surplus robot of the fixed base structure.

In this experiment, the robot can recognize the object at any position and capture the object at the target location.

The spatial position of the object is estimated using the mapping relationship between the pose of the active camera and the object position in the image.

Also, using the homogeneous matrix by coordinate transformation, mobile robot and working robot are not considered as two independent systems, but as one system.

Finally, in order to reach the estimated position out of the working robot's working space, the optimal path is generated according to the optimum values of curvature and speed at every control period.

Through simulation and experiment, we showed that specific tasks could be performed by overcoming the limitations of working robots under the cooperation of mobile robots.

In the mobile autonomous robot system configuration, in order to control many tasks related to the control of each joint and the control of the camera mechanism in real time, a distributed control method is adopted in which a plurality of controllers perform control through a network.

In order to efficiently place a task or mobile robot on a specific task, the robot's working posture with respect to performing the task should be considered first. In the case of such a system, since the controllers of each robot unit are separated from each other, in this study, a task separation method is proposed in order to effectively control the robot so that the entire robot system has the desired performance. This control method allows each robot to perform a task without collision of the task content. As can be seen from the experimental results, it is impossible to know at what point the mobile robot should cooperate without measuring each posture of the work robot, and the work robot falls into the singularity and cannot perform the next work.

Accordingly, in the present invention, when the TOMM is used as the index of the division-acquisition algorithm of the work and the cooperative control performance, the work robot takes an optimal posture to work and performs the work continuously and smoothly by the cooperation of the mobile robot at a specific point in time. Could know. At this time, the mobile robot had several disturbances when considering the friction between the mechanical part and the bottom surface, but the PID controller could obtain relatively precise characteristics, and the mobile robot could play the role of sufficient base.

In addition, the system of the present invention can detect the state of the robot itself by the addition of a self-failure, diagnostic functions, and can indicate the failure site and state can have a user's convenience and safety.

In the present invention, through the control of a mobile robot including a robust disturbance overcoming algorithm, it can be applied to transmission towers and other applications in addition to special bridge structures, and can be used for future-oriented research as follows by establishing stability analysis technology of the system.

In the robot system, each algorithm is applied to the design of controllers for different applications, in addition to the special bridge structures, it is also used for supervision and maintenance measurement of the deterioration part of the transmission line tower, and it is used for the education information system using virtual reality, and the real-time driving information system of the intelligent mobile robot. It can be used for construction of civil engineering structures and supervision sites that require remote work.

An embodiment of the present invention described above and illustrated in the drawings should not be construed as limiting the technical spirit of the present invention. The protection scope of the present invention is limited only by the matters described in the claims, and those skilled in the art can change and change the technical idea of the present invention in various forms. Therefore, such improvements and modifications fall within the protection scope of the present invention as long as it will be apparent to those skilled in the art.

Claims (3)

In a mobile autonomous robot system by cooperative control of a working robot and a mobile robot, the system includes a higher controller including a main controller connected to an active camera including a CCD camera equipped with three or more three-dimensional distance recognition. A work robot connected to the main controller and controlled by a 6-axis motor controller; It is connected to the main controller 3 controllers for the three-axis control of the mobile robot and CAN controller for the network control of one motor controller for the Pan / Tilt control of the active camera; The main controller, the upper controller, acquires image information and robot status information, processes image processing, robot operation plan, and transmits commands to the lower controller. The pan / tilt of the active camera is controlled by the lower controller so that each axis can be controlled at the same time, and the lower controller that controls the speed of each wheel of the mobile robot is configured to be a PID controller so that it shows robustness to the dynamics caused by the movement of the robot. Mobile autonomous robot system based on the cooperative control of a mobile robot and a work robot, characterized in that. According to claim 1, wherein the mobile autonomous robot system is based on the cooperative control of the mobile robot and the work robot, characterized in that the work robot is used for maintenance, repair, reinforcement work by the mobile robot and the work robot cooperative control Mobile autonomous robot system having a. The method of claim 2, wherein the acquisition of information required for the maintenance, repair, and reinforcement of the structure is performed using a sensor, but the sensor is obtained by interlocking sensors including a laser, an ultrasonic wave, and an infrared ray. A mobile autonomous robot system based on the cooperative control of a mobile robot and a work robot, further comprising a self-monitoring system having a self-test function.

Images