Control reconfiguration

About: Control reconfiguration is a research topic. Over the lifetime, 22423 publications have been published within this topic receiving 334217 citations.

Distributed control of modular and reconfigurable robot with torque sensing

Abstract: A major technical challenge in controlling modular and reconfigurable robots is associated with the kinematics and dynamic model uncertainties caused by reconfiguration. In parallel, conventional model uncertainties such as uncompensated joint friction still persist. This paper presents a modular distributed control technique for modular and reconfigurable robots that can instantly adapt to robot reconfigurations. Under the proposed control method that is based on joint torque sensing, a modular and reconfigurable robot is stabilized joint by joint, and modules can be added or removed without the need to adjust control parameters of the other modules of the robot. Model uncertainties associated with link and payload masses are compensated using joint torque sensor measurement. The remaining model uncertainties, including uncompensated dynamic coupling and joint friction, are compensated by a decomposition-based robust controller. Simulation results have confirmed the effectiveness of the proposed method.

Efficient reconfiguration algorithms for degradable VLSI/WSI arrays

Abstract: The development of efficient algorithms for constructing a flawless subarray from a defective VLSI/WSI (wafer scale integration) array is discussed. The array consists of identical elements such as processors or memory cells embedded in a switch lattice in the form of a rectangular grid, in contrast to the redundancy approach in which some elements are dedicated as spares, all the elements in the degradation approach are treated in a uniform way. Each element can be either fault-free or defective, and a subarray which contains no faulty element is derived under constraints of switching and routing mechanisms. Although extensive literature exists concerning spare allocation and reconfiguration in arrays with redundancy, little research has been published on optimal reconfiguration in a degradable array. A graph formulation is used to describe the problem, and reconfiguration is found to relate to finding an independent set of a graph. Efficient heuristic algorithms are presented to determine a target subarray from the defective host array. >

Reconfigurable spacecraft attitude takeover control in post-capture of target by space manipulators

Abstract: Most current research on reconfigurable control system puts emphasis on reconfiguration for adapting to actuator failures. However, the reconfigurable control system is necessitated for spacecraft attitude takeover control in the application of capturing target spacecraft whose fuel is exhausted to extend its operational lifetime by supplying them propulsion, navigation and guidance services. In this scenario, the capture of target spacecraft by space manipulators will cause a large shift in the dynamics of the service spacecraft. Not only do the mass properties change, but also does the thruster configuration. The changes in the mass, center of mass and inertia of the combined spacecraft will cause changes in the equivalent force exerted by each thruster. In this paper, considering the changes of thruster configuration and the control reallocation, a reconfigurable control system is designed for spacecraft attitude takeover control in post-capture of target by space manipulators in order to adapt to changes in the mass properties. The unknown inertia properties of target spacecraft in the system constitute a formidable technical challenge for controller design. Therefore, a modified adaptive dynamic inverse controller is proposed to provide global asymptotic stability in the presence of model uncertainties and nonlinearities. Moreover, by the null-space intersections control reallocation method, the thrust forces of service spacecraft can be redistributed and satisfy some constraints. Numerical simulations validate the feasibility of reconfigurable spacecraft attitude takeover control with large center of mass shifts and unknown inertia properties.

Assessing document relevance with run-time reconfigurable machines

Abstract: Free text database searching is a natural candidate for acceleration by run time reconfigurable custom computing machines. We describe a fully pipelined search machine architecture for scoring the relevance of textual documents against approximately 100 relevant target words, with provision for limited regular expression matching and error tolerance. An implementation on the SPACE custom computing platform indicates that throughput in the order of 20 megabytes per second is achievable on ALgotronix FPGAs if a locally synchronous design style is adopted and global communications minimized. Partial reconfiguration of the datapath at run time, in around 3 seconds, serves to maximize the density of data storage on the machine and correspondingly avoid costly input from the environment.

Parallel stereocorrelation on a reconfigurable multi-ring network

Abstract: A reconfigurable network termed as the reconfigurable multi-ring network (RMRN) is described. The RMRN is shown to be a truly scalable network in that each node in the network has a fixed degree of connectivity and the reconfiguration mechanism ensures a network diameter of O(log2 N) for anN-processor network. Algorithms for the two-dimensional mesh and the SIMD or SPMD n-cube are shown to map very elegantly onto the RMRN. Basic message passing and reconfiguration primitives for the SIMD/SPMD RMRN are designed for use as building blocks for more complex parallel algorithms. The RMRN is shown to be a viable architecture for image processing and computer vision problems using the parallel computation of the stereocorrelation imaging operation as an example. Stereocorrelation is one of the most computationally intensive imaging tasks. It is used as a visualization tool in many applications, including remote sensing, geographic information systems and robot vision.