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Faced with the problem of time-delay in the structural active control, the active control based on the output vector prediction in the structural vibration is proposed. Also, the thesis devises a plan of forecast active control, where the gray model GM (1, 1) is used as the prediction model and the Matlab program is applied to the Computer Simulation Analysis. Adopting the plan in the aseismatic control...
Multi-view 3D surface reconstruction is typically formulated as minimizing an appropriate energy functional, which tends to find the empty set, i.e. an undesirable result, especially when cooperating only with a boundary term. So generally a regional term is employed, which indicates inside or outside of the surface. It is, however, the challenge because inherently there is no straightforward way...
Searching radiation sources in a nuclear environment plays an important role in securing nuclear safety. In this paper, we present a search strategy of a mobile robot for radiation sources in an unknown environment. The proposed method enables a mobile robot to find radiation sources autonomously because it is harmless to expose the robot to an environment contaminated by radiation. Previous work...
The measurement quality of Global Navigation Satellites Systems (GNSS) during marine operations will vary over time. Inherently, GNSS quality changes should be handled when GNSS is utilized as aid in inertial navigation systems. In this paper we present an observer for estimating position, velocity and attitude with time-varying gains for highperformance sensor fusion based on GNSS quality and other...
In this communication, we propose a four-parameter fractional derivative Zener model for modeling of a viscoelastic element connected into a robotic system. We used force-displacement relation in order to obtain generalized forces of the element connected to two different bodies in the system. Generalized forces of the element are derived using the principle of virtual work. In order to obtain numerical...
Playing an important role in security patrol, invader hunting and space exploration, formation control is the typical problem of multi-agent cooperation control system. In order to solve the problem of fixed position assignment and long time to reach the target in traditional artificial force model, a formation control method is proposed based on artificial force with exponential form. Agents' positions...
A novel adaptive object impedance control strategy is presented for dual-arm cooperative humanoid manipulators. A general impedance scheme comprising internal impedance control and object impedance control is adopted, which aims at conferring a compliant behavior both in end-effector level and object lever. The adaptation law for the stiffness and damping of object impedance is derived from Lyapunov...
Sliding mode based roll-pitch-yaw integrated attitude and acceleration controller for a fin-controlled skid-to-turn(STT) missile is proposed. In terms of aerodynamics, the missile model has severe nonlinearities and coupling effect between input channels and roll-pitch-yaw angles that make the controller design challenging. Moreover, the controller should be designed for the entire flight envelope...
Active constraints and virtual fixtures are popular control strategies used within human-robot collaborative manipulation tasks, particularly in the field of robot-assisted surgery. Recent research has shown how active constraints, which robotically regulate the motion of a tool that is primarily manipulated by a human, can be implemented in dynamic environments which change and deform throughout...
Detection of polymorphic malware variants plays an important role to improve information system security. Traditional static/dynamic analysis technologies have shown to be an effective characteristic that represents polymorphic malware instances. While these approaches demonstrate promise, they are themselves subject to a growing array of countermeasures that increase the cost of capturing these malware...
Direct Instantaneous Torque/Thrust Control (DITC) is a high performance technique, based on selecting the inverter's “optimum voltage vector” thus allowing Force and Flux to quickly reach the reference values. The result is a very good dynamic response. In this paper, we address the direct instantaneous thrust control of a 3-phase 6/4 linear switched reluctance actuator (LSRA) by Pulse-width modulation...
This paper proposes a novel set-point control method of a musculoskeletal system by combining a feedforward and feedback manner to complement each drawback each other. In our previous work, a feedforward positioning method of the musculoskeletal arm model was proposed which does not need any realtime sensory information. Its performance, however, depends on a muscular arrangement and an attitude of...
We present a robot capable of both (1) dynamically perching onto smooth, flat surfaces from a ballistic trajectory and (2) successfully transitioning to a climbing gait. Merging these two modes of movement is achieved via a mechanism utilizing an opposed grip with directional adhesives. Critical design considerations include (a) climbing mechanism weight constraints, (b) suitable body geometry for...
This paper presents a control framework for arm/hand systems aimed at controlling internal forces exchanged between the fingers and the grasped object, and enforcing a compliant behavior in presence of environmental interactions. A dynamic planner computes the motion references for the fingers by using the feedback of the contact forces, while an impedance control, in which dynamic effects exerted...
A stabilization and control technique developed for steering swarms of unmanned micro aerial vehicles is proposed in this paper. The presented approach based on a visual relative localization of swarm particles is designed for utilization of multi-robot teams in real-world dynamic environments. The core of the swarming behaviour is inspired by Reynold's BOID model proposed for 2D simulations of schooling...
This paper considers the problem of directing a family of underactuated ships to formation tracking a set of closed orbits and achieve attitude synchronization. It shows that our previous concentric compression design is useful to the coordinated motion of underactuated ships. The condition that the total linear speed of each ship is greater than zero is ensured by introducing a potential function...
Leakage is the most important factor for unaccounted losses in any pipe network around the world. Most state of the art leak detection systems have limited applicability, lack in reliability and depend on user experience for data extraction. This paper is about a novel system for robotic pipe integrity inspection. Unlike existing systems, detection in based on the presence of a pressure gradient in...
We describe a full-featured simulation pipeline implemented in the MuJoCo physics engine. It includes multi-joint dynamics in generalized coordinates, holonomic constraints, dry joint friction, joint and tendon limits, frictionless and frictional contacts that can have sliding, torsional and rolling friction. The forward dynamics of a 27-dof humanoid with 10 contacts are evaluated in 0.1 msec. Since...
This work focuses on the modeling and control of robotic manipulators powered by compliant actuation systems equipped with clutches for providing friction torque on demand. A novel control scheme is proposed for modulating the clutch friction torque in this particular class of compliant actuators to make the robot operate in “Rigid mode” when it does not interact with the environment to achieve high...
Underactuated mechanisms are commonly used in robotic hands and grippers to improve their ability to adapt to the shape of an object. These underactuated mechanisms can be characterized by their global stiffness as measured by their actuator. Using this with self-adaptive fingers, it is possible to elaborate equations highlighting the relationship between the stiffness measurements and the contact...
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