This paper deals with current sharing problem for interconnected power converters in DC microgrids. Specifically, it considers as a case study a multi-input converter (MIC), including two voltage sources connected to a common DC bus with a bulk capacitor through two parallel synchronous boost converters and an aggregated load modelled as an ideal current source connected to the DC bus. The dynamics related to current distribution can be controlled without impacting the voltage regulation. This decoupling is performed without resorting to a time-scale separation, which would lower the achievable performance. Instead, unilateral coupling can still be achieved by using a new control structure where the voltage regulation is independent of the current splitting. The proposed strategy, based on dynamic allocation theory, achieves a fast voltage response with an optimal current distribution among the converters, considering the current limits, the dynamic response, and the efficiency of the individual converters. The proposed solution is tested by numerical simulations in a Matlab/Simulink environment.

We present theoretical and experimental results regarding the development and the control of a two-link robotic arm with remotized actuation via rolling diaphragm hydrostatic transmissions. We propose a dynamical model capturing the essential dynamics of the developed transmission/robot ensemble and implement a control strategy consisting of two nested loops, the inner one performing high-bandwidth joint torque regulation and the outer one producing various types of compliance responses for effective human–robot interactions. Extensive sets of experiments, testing both the low-level torque controller and the high-level compliance controller, confirm the effectiveness of the proposed hardware-software remotization architecture.

In cooperative manipulation tasks, load allocation is a crucial step in order to solve the intrinsic redundancy of the system. The desired wrench needs to be suitably distributed between the end-effectors to implement the desired motion of the manipulated object. In this framework, both the grasp kinematics and the individual capacities of each manipulator provide relevant constraints. On one hand, the end effector wrenches act on the object via the grasp geometry. On the other hand, the individual admissible payload further depends on the current configuration of the robots. In this paper we focus on a heterogeneous cooperative manipulation setting and we design a proper allocation strategy to distribute the desired object wrench, considering both constant and time-varying constraints for the load distribution. The relevance of our findings is illustrated by means of an experimental study involving two anthropomorphic robots manipulating a common object.

The problem of online calibration and recalibration of continuous glucose monitoring (CGM) devices is considered. Two different parametric relations between interstitial and blood glucose are investigated and constructive algorithms to adaptively estimate the parameters within those relations are proposed. One characteristic is the explicit consideration of measurement uncertainty of the device used to collect the calibration measurements. Another feature is the automatic detection of fingerstick measurements that are not suitable to be used for calibration. Since the methods rely on the solution of linear matrix inequalities resulting in convex optimization problems, the algorithms are of moderate computational complexity and could be implemented on a CGM device. The methods were assessed on clinical data from 17 diabetic patients and the improvements with respect to the current state of the art is shown.

In this paper, an experimental vehicle developed at the University of Trento, Italy is illustrated. For this vehicle, the raw data of the engine torque is estimated from the experimental longitudinal velocity and acceleration of the vehicle, obtained from a sequence of automated maneuvers. Then, a suitable polynomial parametrization of the engine torque map is presented, which allows for an elegant formulation of the least squares parameter identification. Finally, a control law based on a backstepping approach is proposed, that globally asymptotically stabilizes the nonlinear dynamics to the reference speed setpoint. The proposed control law is appealing because it induces a linear relation between the reference and the actual speed and its parameters can be tuned following a PD approach. Preliminary experimental results match somewhat the predicted behavior of the simulation analysis of the proposed controller.

In this paper, we propose a nonlinear antiwindup scheme to guarantee stability and local performance recovery on Euler-Lagrange systems subject to input magnitude saturation. The antiwindup scheme consists in a dynamic augmentation to the baseline control system which, based on nonlinear analysis, is shown to induce global asymptotic stability and local exponential stability on the overall control scheme. To induce desirable closed-loop performance on a specific system, two parameters of the antiwindup law can be tuned for each position variable of the Euler-Lagrange system, similar to the tuning procedure for proportional-derivative gains. Simulation results are reported showing the behavior of the proposed antiwindup law on the model of a popular industrial robot. The resulting responses confirm the effectiveness of the antiwindup scheme, both for set-point regulation tasks and for trajectory tracking tasks where the saturation nonlinearity is repeatedly activated.

In this paper we summarize the anti-windup construction suggested by Teel et al. (1997) for Euler-Lagrange systems and apply it to a SCARA robot controlled by a windup-prone decoupling PID controller. It is shown through simulation that the anti-windup design guarantees the local decoupled linear performance in. addition to global set-point tracking.

The paper discusses the modelling issues for a two link flexible robot arm. The exact dynamic model of the robot arm is derived, and approximate forms suitable for the analysis and control design are proposed. The approach used here to derive an approximate finite dimensional model of the flexible robot arm is based on the Ritz expansion method. Simulations and experimental tests have been carried out to validate the approximate dynamic model of the robot.