This paper studies the problem of fault detection and isolation (FDI) for multi-agent systems (MAS) via complex Laplacian subject to actuator faults. A planar formation of point agents in the plane using simple and linear interaction rules related to complex Laplacian is achieved. The communication network is a directed, and yet connected graph with a fixed topology. The loss of symmetry in the...

A new method for the control reconfiguration of stable Hammerstein systems after actuator faults is described. The class of Hammerstein systems contains input-saturated systems, which are ubiquitous in practice. The new reconfiguration approach uses a virtual actuator that permits to keep the nominal controller in the loop. The concept of virtual actuators is extended to reflect the nonlinear p...

The paper presents the virtual prototype of an automotive suspension system with force generator actuator. The active suspensions use sensors to measure the accelerations of sprung mass and unsprung mass, the analog signals from the sensors being transmitted to the controller, which communicates with the force actuator. In this way, the passenger comfort and car stability are simultaneously imp...

We propose a robust actuator fault tolerant control strategy for systems with linear parameter varying (LPV) uncertainty model description. The scheme employs a set-based robust fault detection and identification (FDI) approach and a bank of virtual actuators (VA). An interesting feature is that the virtual actuators are used both for FDI and controller reconfiguration (CR) tasks. The robust FD...

Robots typically have an individual actuator at each joint which can result in a non-intuitive and diicult control problem. In this paper we present a control method in which the real joint actuators are used to mimic virtual actuators which can be more intuitive and hence make the control problem more straightforward. Our virtual actuator control method requires a solution to the force distrib...

In this paper, a force-controllable compact actuator module for a wearable hand exoskeleton system is proposed. To interact with virtual objects naturally with a hand exoskeleton, a small actuator module, which can generate the desired force accurately, is highly required. In the proposed actuator module, a series elastic actuator (SEA) mechanism was applied for the force mode control. Based on...

In this paper, a fault tolerant control method for linear parameter varying (LPV) systems using a virtual actuator and a virtual sensor is proposed. The basic idea of the method is to insert a reconfiguration block, which consists of an LPV virtual actuator and an LPV virtual sensor, between the plant and the nominal controller such that the fault tolerant goal is achieved without re-designing ...

This paper proposes a new fault-tolerant control (FTC) method for discrete-time linear parameter varying (LPV) systems using a reconfiguration block. The basic idea of the method is to achieve the FTC goal without redesigning the nominal controller by inserting a reconfiguration block between the plant and the nominal controller. The reconfiguration block is realized by an LPV virtual actuator ...

A modification of digital controller algorithms, based on the introduction of a virtual reference value, which never exceeds active constraints in the actuator output is presented and investigated for some algorithms used in single-loop control systems. This idea, derived from virtual modification of a control error, can be used in digital control systems subjected to both magnitude and rate co...

In this paper, virtual actuators are proposed as a Fault Tolerant Control (FTC) strategy for switching Linear Parameter Varying (LPV) systems subject to actuator faults. The overall solution relies on the addition of a virtual actuator block that keeps the stability and some desired performances without the need of retuning the nominal controller. It is shown that the design can be performed us...