II. Control system of the elevator
4. Conclusion
In this paper, we have applied MapReduce to compute n-gram statistics for the language model. Moreover, the ideal environment which has a SGE installed in it may provide a significant improvement for Kaldi toolkit. Both of these applied platforms decrease the processing time in a sufficiently great way. Further investigations will be conducted to explore new features of distributed computing.
To sum up, we will continue to improve the Speech Recognition Research in terms of parallelization.
Acknowledgments
The authors would like to thank the National Laboratory Astana for the resources used to perform these investigations and Karabalayeva M. and Yessenbayev Zh. for providing results of audio decoding that added a value in better analysis for this paper.
References:
1. Povey, D, Ghoshal, A, Boulianne, G, Burget, L, Glembek, O, Goel, N, Hannemann, M, Motlicek, P, Qian, Y, Schwarz, P, Silovsky, J, Stemmer, G & Vesely, K 2011, “The Kaldi Speech Recognition Toolkit”, IEEE 2011 Workshop on Automatic Speech Recognition and Understanding
2. Zaharia, M 2014, Introduction to MapReduce and Hadoop, UC Berkeley RAD Lab 3. MapReduce, viewed 15 April 2016, URL https://hadoop.apache.org
4. Sun microsystems 2009, Sun N1 Grid Engine 6.1 User's Guide, Santa Clara, CA, USA 5. Open Grid Engine, viewed 15 April 2016, URL http://gridscheduler.sourceforge.net
41 UDC 004.5
NURGALIYEV K. S.1, KAPSALYAMOV A. B.1, SERIMBETOV B. A.2
STUDY AND DEVELOPMENT OF A DESKTOP HAPTIC INTERFACE FOR TELEOPERATION
(1Master's Degree student of the Information Technologies Department, Kazakh University of Technology and Business, Astana, Kazakhstan,
2Associate Professor, Candidate of Technical sciences, Head of the Information Technologies department, Kazakh University of Technology and Business, Astana, Kazakhstan) Abstract
Teleoperation systems provide the users with a possibility to perform sophisticated tasks in distant environments. A haptic interface can allow the operator to use not only visual and audial senses but also the tactile senses to perceive his/her environment and provide more accurate and precise control over the task that is being performed by the robot remotely. This overview is a description of a haptic interface used for teleoperation of the complex anthropomorphic robotic systems in an intuitive way. The system allows six degrees of freedom when connected with two points of the human limb. Force feedback is provided at the users fingertips when the robot is in contact with an object recognized as an obstacle.
Keywords: degree of freedom, haptic, tactile, interface, simulation, design I. Haptic interface
Haptic interface is a synergy between human tactile senses and a robotic system, which consists of three main components: (1) the electromechanical system with a certain number of degrees of freedom (DOF); (2) the teleoperated robotic device; (3) and the algorithm from the computer or any other programmable machine that provides the transmission of the commands. [1]
It is one of the growing areas in human computer interaction, which deals with sensory communication with robotic systems by applying motions, vibrations or forces to the user.
Teleoperation of the robots is a term used to name the remote control of a robotic system to make it perform a certain task given by the operator. [2] Haptic interfaces enable manual interactions with virtual environments or teleoperated remote systems using force feedback.
A haptic interface can be mainly of two kinds: a grounded system, which has its base, fixed with the wall or the floor[3]; and a wearable system where the main fixing point is represented by the human body [4], [5]. The advantages of the first type are the capability to deliver a higher force feedback and to spare the user sustaining the weight of the whole system. While the second type generally has a bigger workspace and it results more natural because it is normally wearable and repeats human anatomy and ergonomics. In comparison with classical joysticks the main advantages of using an interface that connects with the forearm is that the operator can give the orientation commands to the robot not using the wrist but the entire arm. However, manipulating the end-effector of the robot using only the fingertips provides larger amount of precision. By applying less force, the operator is then able to maintain more complex and more wide-scale performance from the teleoperated robot. The main objective of the present work is to describe this particular approach, as well as to show a simulation methodology using the programming platform.
The Interface Design section includes the technical description of the hardware and all the electrical components used during the building process. The chosen methodology allows to manipulate the robotic system and to visualize the robots behavior from different perspectives. The discussion of the results with appropriate outflow of Conclusion part will summarize the paper and give a clearer understanding of what purposes this robot might serve and in what fields it might be implemented.
The suggestions on the future work regarding the improvement of this robots design will be provided prior to the end of this paper.
42
Fig. 1 - A force feedback device called The PHANToM by SensAble Technologies Inc
Haptic Robots such as the PHANToM was considered as a starting point of brainstorming in order to decide what design to use, what interface to create, and what features to add. Concisely, some users do not notice meaningful differences in hardness in an experiment where the users recognize the hardness of an object or the workspace size although those users manipulate different types of haptic interface devices [6]. PHANToM is a popular linkage-based haptic device (fig. 1).
The position and orientation of the pen are tracked through encoders in the robotic arm. Three degrees of force, in the x, y and z, directions are achieved through motors that apply torques at each joint in the robotic arm. The arm tracks the position of the pen (end-effector) and as a result, it is required to determine the proper joint angles and torques necessary to exert a single point of force on the tip of the pen. An alternative to a linkage-based device is one that is tension-based. Instead of applying force through links, cables are connected to the point of contact in order to exert a force [7]. Encoders determine the length of each cable. From this information, the position of a gripper can be determined. Motors are used to create tension in the cables, which results in an applied force at the grip. The pen as the end effector is a convenient way to perform manipulation tasks on the robot, depending on the environment it is going to be used in. Our robot provides 3 DOF that we are able to measure, but the end-effector is connected through a spherical base, providing another 3 DOF but this time, only to bring the joints to proper movement.
Robot motion of teleoperated systems is usually controlled by system operators with the help of a camera mounted on robot or inspecting the area from above. Although vision systems provide much information of the environment, they require much attention from the operator. To overcome this problem, haptic devices provide operators with the additional sense of feeling the robot workspace, thus making it easier to avoid obstacles and reducing the average number of collisions. Usually, operators have to drive manually the mobile robot through obstacles by explicitly specifying the robots angular and linear velocity. By doing so, they are fully in charge of the robot motion and as a clear viewpoint of the robot environment may sometimes not be available, they could accidentally drive the robot to collisions or choose longer paths than optimal ones. One possible way to resolve this might be using a vibrating motor to give a force feedback to the operator in order to notify them without blocking their visual or audial perception during the work.
The mobile robot haptic teleoperation system consists of two sides: the Master side, which contains the haptic device and the master station with the map-building module and the Slave side, which contains the mobile robot and a slave robot server with the behavior and the localization module for the exploration of the unknown environment [8]. According to A.Tatematsu and Y. Ishibashi [6], the efficiency of systems work is higher in the case where the workspace is uniformly mapped to the virtual space in the directions of the x, y, and z-axes than in the case where the workspace is individually mapped to the virtual space in the direction of each axis so that the mapped workspace size corresponds to the virtual space size.
43 II. Interface design
Our research is devoted to developing the principles and tools necessary for the realization of the advanced robotic and human-machine systems capable of haptic interaction. Considering a certain type of sensors, it is necessary to focus on ACP Single-Turn Trimmer potentiometer CA9H5 1K with shaft (fig. 2). There is number of terms in the electronics industry used to describe certain types of potentiometers, where a trimmer pot is included. It can be described as a trimming potentiometer which is adjusted once or infrequently for ”fine-tuning” of an electrical signal. The user in order to move the robot should perform a hand movement. This different movement is sensed by potentiometer attached to each joint. Output current should be monitored continuously to protect drive mechanics and motor; switch-off limit can be adapted by trimmer potentiometer to suit individual drive used.
Fig. 2 - CA9H5 1K trimmer pot
Generally, a potentiometer can serve as a position sensor for the haptic feedback loop controlling the motor. To test methodology, study and develop a haptic interface that can be used to teleoperate complex anthropomorphic robotic systems in an intuitive way, one of the first approaches has been accomplished. A Simulink model was created (fig. 3). Regarding this, Analog Input block corresponds to Real-Time Windows target block in order to receive data from potentiometers for each joint position. Scope block retranslates data to MATLAB Workspace. Math Function block enables a user to convert the data from potentiometers mounted on joints to radians.
Fig. 3 - First Simulink model and Matlab-Potentiometer circuit
44 III. Experimental results and future work
After the hardware of the interface assembling and established the connection with the software we run tests to observe the behavior of the system. Despite several errors that were then adjusted the haptic interface simulation might to give good results in terms of overall performance.
That includes the response of the hardware to software and vice-versa.
Fig. 4. Model of Desktop Haptic Interface
Desktop Haptic Interface (fig. 4) would be able to read the signals sent from potentiometers and responded within short amount of time. Then the virtual model of STAUBLI and a box representing the obstacle can be added. Both systems and models can make correct movements while being operated by the user. For testing whether it is even possible to use the output of the haptic system as the input for the actual robot the data should be recorded in a separate file and be sent it to the input system of STAUBLI. As a result, the robot responds accordingly, with the vibrations and cautions related to obstacle being taken into account.