The Experts below are selected from a list of 5382 Experts worldwide ranked by ideXlab platform

M. O. Tokhi - One of the best experts on this subject based on the ideXlab platform.

  • dynamic modelling and linear quadratic gaussian control of a twin rotor multi input multi output system
    Proceedings of the Institution of Mechanical Engineers Part I: Journal of Systems and Control Engineering, 2003
    Co-Authors: S M Ahmad, Andrew J. Chipperfield, M. O. Tokhi
    Abstract:

    This paper presents an investigation into the modelling and control of a one-degree-of-freedom (1 DOF) twin-rotor multi-input multi-output (MIMO) system (TRMS). The behaviour of the TRMS in certain aspects resembles that of a helicopter. Hence, it is an interesting identification and control problem. A dynamic model characterizing the TRMS in hover is extracted using a black-box system identification technique. The extracted model is employed in the design of a feedback linear quadratic Gaussian compensator, namely the stability augmentation system (SAS). This has a good tracking capability but requires high control effort and has inadequate authority over residual vibration of the system. These problems are resolved by further augmenting the system with a Command Path prefilter, resulting in the Command and stability augmentation system (CSAS). The combined feedforward and feedback compensator satisfies the performance objectives and obeys the actuator constraint. The control law is implemented in realtime on the TRMS platform.

S M Ahmad - One of the best experts on this subject based on the ideXlab platform.

  • dynamic modelling and linear quadratic gaussian control of a twin rotor multi input multi output system
    Proceedings of the Institution of Mechanical Engineers Part I: Journal of Systems and Control Engineering, 2003
    Co-Authors: S M Ahmad, Andrew J. Chipperfield, M. O. Tokhi
    Abstract:

    This paper presents an investigation into the modelling and control of a one-degree-of-freedom (1 DOF) twin-rotor multi-input multi-output (MIMO) system (TRMS). The behaviour of the TRMS in certain aspects resembles that of a helicopter. Hence, it is an interesting identification and control problem. A dynamic model characterizing the TRMS in hover is extracted using a black-box system identification technique. The extracted model is employed in the design of a feedback linear quadratic Gaussian compensator, namely the stability augmentation system (SAS). This has a good tracking capability but requires high control effort and has inadequate authority over residual vibration of the system. These problems are resolved by further augmenting the system with a Command Path prefilter, resulting in the Command and stability augmentation system (CSAS). The combined feedforward and feedback compensator satisfies the performance objectives and obeys the actuator constraint. The control law is implemented in realtime on the TRMS platform.

Y. Ishimaru - One of the best experts on this subject based on the ideXlab platform.

  • human machine cooperative tele driving system with Command Path compensation algorithm
    International Conference on Advanced Intelligent Mechatronics, 2005
    Co-Authors: Y. Kunii, M. Moriyama, S. Nagatsuka, Y. Ishimaru
    Abstract:

    In operation environment with communication time delay, it's difficult to compose a closed loop control structure between a master and slave system, and then, some scheme to achieve the stability is necessary. In this paper, we discuss and evaluate our proposed human machine cooperative tele-drive system consisted of global and local Path-planning, for a long range traversability. Operator can Command any desired Path as waypoint sequences, by using 3D terrain model which was measured as DEM by on-board sensor of a rover and then transmitted to the ground and evaluated with dangerousness. For corresponding to unknown obstacle, a conventional autonomous Path-planning algorithm is applied between each waypoint. In addition, a rover is up-dating environment data set, and then it causes the difference between terrain data used for Commanding of an operator and for traversing of a rover. Therefore, we have to compensate waypoints by using the latest measurement data which can be assumed more reliable than previous data, for corresponding to the difference automatically. Here, the difference is assumed as the distortion between each data set, and compensated by using a distortion compensation matrix which is the mapping between the old and new terrain data sets. Simulation and experimental results and its evaluations, by using the rover test-bed, are mentioned

  • Command Path compensation algorithm for rover tele-driving system and its evaluation
    ICAR '05. Proceedings. 12th International Conference on Advanced Robotics 2005., 2005
    Co-Authors: Y. Kunii, M. Moriyama, S. Nagatsuka, Y. Ishimaru
    Abstract:

    In this paper, we discuss tele-driving method for a long driving of a mobile robot in the natural field and experimental results are shown. An operator uses virtual world simulator to make Command Path. The virtual environment of this simulator is constructed with measurement data from a rover. We have, however, a communication delay between the control station and the remote site. So, there is the difference between old map data which operator used for Path planning and new data, which a rover is tracking on. The operator's Path Command has less reliability to avoid obstacles and to reach the goal. Therefore, to make high reliability of operator's Command, we propose Command-data compensation (CDC), which compensates this difference as the distortion of the environmental map

Aoki Toshimichi - One of the best experts on this subject based on the ideXlab platform.

  • machine learning device robot system and machine learning method for learning operations of robot and laser scanner
    2018
    Co-Authors: Murakami Yoshinori, Aoki Toshimichi
    Abstract:

    A machine learning device for learning operations of a robot and a laser scanner, includes a state observation unit observing a state of a tip end of the robot where the laser scanner is mounted and a state of an optical component in the laser scanner as a state data; a determination data obtaining unit receiving at least one of a machining time of the robot where the laser scanner is mounted, a drive current driving the robot, a Command Path of the laser scanner, a passing time in a processable area where the laser scanner performs processing, and a distance between the robot and a part where the laser scanner performs processing as a determination data; and a learning unit learning operations of the robot and the laser scanner based on an output of the state observation unit and an output of the determination data obtaining unit.

Samok Koo - One of the best experts on this subject based on the ideXlab platform.

  • flight test results of automatic tilt control for small scaled tilt rotor aircraft
    International Conference on Control Automation and Systems, 2008
    Co-Authors: Youngshin Kang, Bumjin Park, Changsun Yoo, Yushin Kim, Samok Koo
    Abstract:

    A small scaled flight model of the tilt rotor aircraft for the Smart UAV Program at KARI(Korea Aerospace Research Institute) has been developed and tested. Since the flight characteristics of a tilt rotor aircraft are new to KARI, the scaled model was used as a test bed to evaluate the flight control algorithm for the full scale smart UAV. The flight test of the small scaled model was performed after various ground tests including tethered hover test. The control laws in initial phase consist of rate SAS feedbacks, control surface mixers, a rotor governor and a manual tilt Command Path. A rate feedback SCAS control law was used in order to evaluate the flight characteristics of the tilt rotor aircraft. As the flight test proceeds, an attitude SCAS was added because the attitude of aircraft was not clearly recognized due to the small size and fast speed of the aircraft. The first full conversion to a fixed wing mode was made through the manual tilt Command by the external pilot. And then the automatic conversion was successfully performed by speed hold Command in compliance with a pre-defined conversion corridor. Several problems unexpected were found during flight tests including oscillation of long period mode near helicopter mode, a delayed response to the altitude Command and etc. The flight test results of the small scaled tilt rotor aircraft using an automatic tilt control is described in this paper and the solutions of the problems noticed in the flight test are presented.