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The robustness of discrete iterative learning controller a-gainst initial state state error for discrete-time plant is investigated in this paper. When the initial state remains fixed for each iteration but is different from the desired one, it is shown that the output will converge to a trajectory which is the same as the desired one except the initial point for a traditional D-type discrete iterative...
The paper considers an example of mechanical system with high relative degree: a fully actuated robot with elastic joints and the related control problem. The considered system is characterized by a uniform relative degree five, assuming as available output only the joints' angles. Two different strategies can be exploited to address this control problem. A first possibility is to use a full order...
This paper presents the design, development and implementation of a Hybrid Adaptive Fuzzy Controller (HAFC) suitable for real-time industrial applications. The developed HAFC consists of a weighted combination of the Direct Adaptive Fuzzy Controller (DAFC) and Indirect Adaptive Fuzzy Controller (IAFC) and a gradually activated supervisory controller. The unique feature of the HAFC is that no mathematical...
By using robust control techniques, this paper proposes an adaptive control for rigid robots with the following important features: under a parameter-dependent PE (Persistent Excitation) condition, it gives a guaranteed transient performance of tracking a smooth desired trajectory while assuring the parameter estimation error to go to a residual set of the origin arbitrarily fast. Simulations are...
A computationally effective trajectory generation algorithm of omnidirectional mobile robots is proposed. The algorithm plans a reference path based on Bézier curves for obstacle avoidance. Then the algorithm solves the problem of motion planning for the robot to track the path in a short travel time while satisfying dynamic constraints and robustness to noise. The numerical simulation demonstrates...
This paper investigates the output tracking results of SISO time-delay system using the super-twisting sliding mode control approach. By a system transformation and Padé approximation, the output tracking of time-delay system is transformed into the tracking of a nonminimum phase system. Stable system centre approach is used to approximate this system by a stable one. All the tracking errors and errors...
In far range proximity of GEO on-orbit service, a space robot cannot reach desired position exactly by using two impulses C-W guidance and control law. To overcome this problem, a multiple impulses C-W guidance and control law with mid-correction is proposed. The guidance problem is transformed to nonlinear programming with constraints according to the error of final position. The fuel optimal solution...
This paper describes the development of a fully autonomous quadrotor robot of non-trivial mass (greater than 2kg), payload capacity, and computing power (using an ARM® processor capable of up to 1400 Dhrystone MIPS). Its successful operation is presented and serves to demonstrate the efficacy of a straightforward control scheme implemented in open source Linux.
The purpose of this paper is to present the investigation of impact pressure acting on the hemisphere cylinder when it hits the water. In this paper, a two-dimensional hemisphere cylinder is built to simulate the water-entry problem. The model enters into the calm water verticals with initial velocity in y-direction at 10m/s. The transient flow simulation is carried out using Fluent k-£ turbulent...
Currently in robotics field, various new forms of robots are emerged that are different from existing robots. One of them is the mobile robot having a tensegrity structure. In this paper, the tensegrity is employed for a design of a mobile robot that can be used in irregular environment. But the tensegrity structure is highly nonlinear; so it is very difficult to control. In order to deal with this...
Differential equations with fractional-order derivatives, e.g., the "one-half" derivative, have a long history in mathematics, but have not yet attained mainstream use in engineering and applied science. While applications do exist in modeling specific phenomena such as visco-elasticity and other types of difficult-to-model phenomena, and extensions to control such as in fractional-order...
Autonomous target capturing is the key for space robot to perform on-orbital servicing tasks. To meet the requirement of complex and long-term task, large flexible appendages, such as solar paddles and antenna reflectors are usually mounted on the base of a space robot. Due to the structure vibration, it is very challenging to capture a free-floating target satellite. In this paper, we derived the...
Sourcing skilled labour for agricultural sector has become a tedious job in today's time. There is a need for mechanization of the farming process in order to cope with the lack of manpower. The need of the hour is automation in the field of agriculture. This paper describes an intuitive mechanized robot, which would eliminate the need of manually climbing the Arecanut tree in order to harvest the...
In this paper consensus in second-order multi-agent systems with a non-periodic sampled-data exchange among agents is investigated. The sampling is random with bounded inter-sampling intervals. It is assumed that each agent has exact knowledge of its own state at any time instant. The considered local interaction rule is PD-type. Sufficient conditions for stability of the consensus protocol to a time-invariant...
As the sliding parameter of track is hard-to-measure when Agricultural Tracked Robot (ATR) is moving in complicated farmland environment, an estimation method for sliding parameters of ATR based on UKF is proposed. A kinematics equation and a measurement equation of ATR are deduced by kinematics principle, and then the precision position parameters of ATR is calculated. Sliding parameters which cannot...
A single port surgery has merits as small scar and little physical burden of subject while it has narrow workspace and small range of operations because of the mechanical limits of the instruments. In order to enlarge the application range of single port surgery, it is important to increase the stiffness and the force of the instruments. This paper presents the design and simulation of a single-port...
As the research in indoor localization moves on, more and more algorithms and systems are proposed by academia as well as industry. However, most approaches are evaluated in simulation or small experiments. The results are often hard to compare as assumptions differ between all settings and the setups vary from lab conditions to real life scenarios. As one of the biggest problems of range based indoor...
In this paper we propose a new skill learning framework based on fusing prior knowledge with programming by demonstration and explorative learning methodologies. Prior knowledge as well as all partially known models guide the search process within the proposed adaptation method. The proposed methodology is based on algorithms originating in iterative learning control and reinforcement learning. The...
This paper describes the mathematical model of the suspension of a robot traction of crawler type, in order to reduce mechanical vibrations caused by operation of the motors and overcoming obstacles in a path. The analysis in reference becomes relevant to the extent that the mechanical vibrations generated damage to the structure and electronic elements in this when the natural frequency of them is...
Interactive reinforcement learning constitutes an alternative for improving convergence speed in reinforcement learning methods. In this work, we investigate inter-agent training and present an approach for knowledge transfer in a domestic scenario where a first agent is trained by reinforcement learning and afterwards transfers selected knowledge to a second agent by instructions to achieve more...
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