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Recent advances in robotics have led to the development of exoskeleton robots that are becoming extensively used in the medical domain, to assist and help people suffering from physical impairments recover mobility. Most of existing controllers designed for position control of exoskeleton robots are linear which may not be suitable for exoskeleton robots having complex structures under heavy uncertainties...
In mobile robotic applications, a common problem is the following of a given trajectory with a constant velocity. Using standard model predictive control (MPC) for tracking of time varying trajectories leads to a constant tracking error. This problem is modelled in this paper as quadrotor position tracking problem. The presented solution is a computationally light-weight target position control (TPC),...
Robot manipulation is one of prerequisites capability for service robot. However, autonomous manipulation remains a challenging problem for robot to implement the task, where robot has physical interactions and mechanical contacts with its environment. To date, learning from demonstration (LFD) has been successfully applied to enable robot to acquire new manipulation skill. Researches on LFD mainly...
The advances of information and communication technologies have impacted in control education. Virtual laboratories are increasingly been used to enhance the way that students interact with simulations. High degree of visualization and interaction offered by modern computers open the opportunity to teach theory fundamentals with a more natural approach. This work describes the use of the robot simulator...
Ball and Plate system is a well-known benchmark to test control strategies because of its multivariable nonlinear coupled dynamics, open loop instability and under actuation. Moreover, presence of parameter uncertainty and external disturbance makes it further challenging and interesting. This calls for a robust controller which not only stabilises the ball on the plate but also makes the ball follow...
Recently, the variety of devices and robots are available for recovering and rehabilitating human disorder patients. In this paper, simple and effective control method utilized for position-impedance control. This method consists of two parts, namely position control in free space and fuzzy impedance control in contact. First, kinematics and dynamics of general 6UPS are discussed. Then SimMechanics...
This paper develops a position control strategy of a multi-rotor system, which moves from an X-Y way-point to another at constant maximum-achievable velocity, and follows rectilinear trajectories between way-points with slight deviations during transients. In achieving this, 2D-spatial displacement breaks down in time domain ramp tracking on each axis through a trajectory generation block. Then, both...
We present a hierarchical controller for a set of two linear synchronous motors with permanent magnets moving in two orthogonal directions for a two degree of freedom high-precision positionning system developed by Newport-France. This system is supposed to realize relatively fast linear displacements from 1 count (4 nm) to 400 mm. A linear displacement of 25mm must be achieved in less than 0.2 s...
In this paper we design a position controller for an autonomous mobile robot, a nonlinear nonholonomic control system. The designed time invariant non smooth stabilizing control law assures limitation of the velocity inputs, human like driving behaviour and smooth trajectories. The global asymptotic stability of the closed loop system is proved using the Lyapunov stability theory and the In-variance...
In the present paper, we described the system architecture of the autonomous mobile robot B21 from RWI focussing on the double control loop implementing the kinematic control together with the underlying drive control. As a highly accurate drive control is taken for granted only the kinematic model is considered for trajectory and position control. In order to manage successfully demanding tasks in...
This paper presents the mathematical model of a hexarotor and the design of the sliding mode controller. The Sliding Mode Control method, which is known to be insensitive to external disturbances and parameter uncertainties, was used to control the altitude, attitude and position of the hexarotor. The Lyapunov's stability theory analysis was used to guarantee the stability of a system. The mathematical...
This study proposes a novel swing-up control strategy for the rotary inverted pendulum based on the feedback linearization and energy control method. After feedback linearization, an energy function is selected to design the swing-up control law where a gain k is chosen according to the trajectories in the phase-plane. It can be found that the time needed for the energy converging to zero is related...
Studying the behavior of a 2-link elastic robotic arm as a manipulator is the purpose of this article. So, all parts of an experimental set up like aluminum links, AC servo motor and its driver, DC motor, strain gauge sensors, high speed digital to analog convertor (DAC) components on an electrical interface board and National Instrument's LABVIEW software package are gathered. In this paper, it is...
Grasping and manipulation of various objects by arms are essential robotic tasks. The dual-arm system in comparison with a single-arm system can grasp objects with larger sizes and shape variations owing to its high degree of task-space redundancy. We report on the development of a dual-arm manipulation strategy suitable for object holding and moving. The controller has master-slave structure. It...
This paper presents the performance validation of the motion control system for integration force and trajectory information. To realize the implementation high-quality motion that includes contact and non-contact motion to robot system, two contradictory systems; force and trajectory control should be synthesized in one control axis. In order to respond to the request, we proposed a motion synthesis...
This paper is devoted to the navigation of an autonomous underwater vehicle (AUV) with a mobile hydroacoustic beacon, which is transported by an autonomous surface vehicle (ASV). Two algorithms for AUV position estimation on base of data from the onboard reckoning system and a synthetic long base line acoustical positioning system (APS) were considered. The first algorithm is based on the discrete...
In this paper, position control for a quadrotor in outdoor environment is designed and is validated by experiment. The quadrotor used in the experiment is equipped by accelerometers which are used by an internal controller to maintain its velocity in the global coordinate, and a global position system (GPS) for location determination. A proportional derivative (PD) controller, utilizing feedback of...
For the first time, a Nooru-Mohammed test was realized using a new kind of loading machine based on gough platform. However, it has been shown that boundary conditions on the concrete specimen are not respected. As a consequence, a new control strategy needs to be developed. This paper aims at applying a well-known control loop based on hybrid force/position law to a loading application. This new...
Concentric-tube robots can offer dexterous positioning even in a small constrained environment. This technology turns out to be beneficial in many classes of minimally invasive procedures. However, one of the barriers to the practical use of a concentric-tube robot is the design of a real-time control scheme. In previous work by the authors, a computationally efficient torsionally compliant kinematic...
In position control of mechatronic devices, velocity feedback is necessary for injecting additional damping to avoid low-frequency fluctuation around desired trajectories. In practice, velocity signal is often obtained by performing Euler discretization on position signal from an optical encoder. However, due to the limited encoder resolution, the obtained velocity signal is corrupted by high-frequency...
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