The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper is devoted to the problem of modeling and position/force tracking for nonholonomic dynamic systems with affine constraints. The rigorous derivation of dynamic model is given. By reasonably introducing so-called internal state vector, a reduced dynamic model, which is suitable for control design, is addressed. Based on the sliding-mode theory, an adaptive control strategy is then derived,...
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...
Most of molecular interactions often occur in feature regions of molecular surfaces such as convex regions, cavities or pockets. In this paper we propose a method to identify these feature regions by expanding the molecular surface to its surrounding spherical surface, that is, a 1-1 mapping is established between them. According to the expansion distance, feature regions can be determined to be concave...
This contribution outlines the main stages of the path that in ten years led James Clerk Maxwell to the introduction of the concept of the electromagnetic field, to the formulation of the electromagnetic theory of light, and to the development of the equations we still adopt for the description of electromagnetic phenomena.
Evolutionary Computation has been suggested as a means of providing ongoing adaptation of robot controllers. Most often, using Evolutionary Computation to that end focuses on recovery of acceptable robot performance with less attention given to diagnosing the nature of the failure that necessitated the adaptation. In previous work, we introduced the concept of Evolutionary Model Consistency Checking...
In this work the design of a linear observer-linear controller robust output feedback scheme is introduced for simultaneous trajectory tracking of position and force in fully actuated robot manipulators. The unknown state-dependent additive nonlinearity influencing the input-output description is modeled as an absolutely bounded “time-varying perturbation”. Generalized Proportional Integral (GPI)...
This paper presents the design steps and implementation results of a hybrid force/position control of the arm. The HFP control is based on a Proportional-Derivative Controller combined with feed-forward position control and multi-stage Infinite Impulse Response (IIR) filter in the joint space position control loop. In the outer loop, a resolved-velocity force control scheme is used. The performance...
By changing the impedance of a manipulator according to the target object and the type of operation, it is possible to improve the operation efficiency. Researches on how to change the impedance of a slave manipulator in a tele-operation system according to the intention of an operator are underway. However, in most cases, change of the impedance is applied to all directions by the same magnitude...
This paper investigates the possibility and fundamental properties of limit cycle walking on slippery road surface. First, we develop the mathematical model of a planar underactauted biped robot with an upper body that walks while sliding on oily/ice floor. Second, we conduct numerical simulations to show that stable gait generation can be achieved by applying a simple output following control to...
For achieving stable grasping and operation of a large object skillfully utilizing the robot's whole-arm and whole-body surface, mathematical theories of modeling and control in consideration of static and dynamic friction forces on the body surface must be developed. On this issue, mathematical modeling for the complicated frictional effects is the most fundamental and difficult task that remains...
To assist operators in precise teleoperation tasks within complex environments, assistance autonomous modules are required. A semi-autonomous path planning module that provides a reliable direction for the operators, is of paramount of importance in this field. This paper proposes a novel assisted method using a fixed camera for guiding the operator to control the manipulator remotely. The method...
A novel approach to path planning for the formation of a swarm of autonomous robots in an unknown environment is presented in this paper. This approach is designed based on the traditional potential fields combined with the rotational vector field. Under the action of this blended vector field, autonomous robots can easily avoid obstacles in order to reach the target position. Furthermore, in this...
The damping of vibrations on aircrafts and rotorcrafts can provide life extension and weight reduction on those structures on which the vibration load is a significant amount of load endurance spectrum. In this work, a hybrid active-passive inertial actuator system is presented. It is based on a ballscrew based actuator, and the power generation is provided by an open windings three phase motor controlled...
In this paper the design of a linear model predictive controller for a triangular floating platform is presented aiming at the stabilization of its linear and angular velocities as well as its position and orientation. Three rotating jets, located at the corners of the platform, control its motion. With this control configuration, the platform is over-actuated. The prediction, and optimization phase...
Paper presents an integrated kinematics and dynamic modeling of the swing, hoist and crowd movements of an electric mining shovel driven by regenerative vector controlled ac drives through ropes and gear reducers. The shovel is modeled as a 4-dof articulated mechanical system with three rotating joints and one prismatic joint. Using the developed models a typical truck loading cycle of digging, swinging,...
The literature on thrust allocation algorithms that is currently available usually focuses on solving only a few of the many facets of the thrust allocation problem at a time. This paper presents a unified thrust allocation algorithm that solves most of the challenges that are faced by the practitioners in one algorithm. This includes controlling thrusters that can change the direction of the generated...
The control design proposed here is based on a general framework of control of nonlinear systems with state-&-input constraints, recently proposed by some of the authors in [1] (summary available in [2]). Thus, this is part of a series of real applications to support the theoretical results. In particular, here the result is applied to the problem of dynamic positioning of ships with nonlinear...
In this paper we present a formation control approach based on Gaussian potential functions, each parametrized by an agent-related control parameter. This results in different characteristics of attractive and repulsive forces among agents and targets, as well as among agents themselves and dependence of the formation's potential structure on the change of agent's configurations. Furthermore, we show...
Robotic-assisted minimally invasive surgery has demonstrated its benefits in comparison with traditional procedures. However, one of the major drawbacks of current robotic system approaches is the lack of force feedback. Apart from space restrictions, the main problems of using force sensors are their high cost and the biocompatibility. In this work a proposal based on Vision Based Force Measurement...
This paper proposes a motion-reproduction method for a multi degree-of-freedom system. For extraction and reproduction of haptic information, motion-copying system was previously proposed. However motion-copying system has a drawback; it is difficult to reproduce the saved motion when the environmental configuration in the motion-loading phase is different from that in the motion-saving phase. There...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.