Henrik Schiøler

Sociable Robots through Self-maintained Energy

Research of autonomous mobile robots has mostly emphasized interaction and coordination that are natually inspired from biological behavior of birds, insects, and fish: flocking, foraging, collecting, and sharing. However, most research has been only focused on autonomous behaviors in order to perform robots like animals, whereas it is lacked of determinant to those behaviours: energy. Approaching to clusted amimal and the higher, collective and sharing food among individuals are major activity to keep society being. This paper issues an approach to sociable robots using self-maintained energy in cooperative mobile robots, which is dominantly inspired from swarm behavior of collecting and sharing food of honey-bee and ant. Autonomous mobile robots are usually equipped with a finite energy, thus they can operate in a finite time. To overcome the finitude, we describe practical deployment of mobile robots that are capable of carrying and exchanging fuel to other robots. Mechanism implementation including modular hardware and control architecture to demonstrate the capabicities of the approach is presented. Subsequently, the battery exchange algorithm basically based on probabilistic modeling of total energy on each robot located in its local vicinity is described. The paper is concluded with challenging works of chain of mobile robots, rescue, repair, and relation of heterogeneous robots.

Trophallaxis in robotic swarms - beyond energy autonomy

The paper considers trophallaxis in robot swarms, which is presented as a concept for resource sharing among individuals inspired by altruistic behaviour in natural populations. A number of elementary problems are identified, such as energy containment, robot morphology, rendezvous motion control and individual resource exchange behaviour. The CISSBot is presented as a design study as well as a proof of concept illustrating how a trophallactic exchange mechanism may be implemented based on batteries in commercially available form factor. A collison free proximity motion control is presented and illustrated by numerical simulation results. A probabilistic Markovian model including relevant effects; mobility, charging, battery exchange and energy consumption is presented and illustrated with numerical examples.

Neural network for estimating conditional distributions

Neural networks for estimating conditional distributions and their associated quantiles are investigated in this paper. A basic network structure is developed on the basis of kernel estimation theory, and consistency is proved from a mild set of assumptions. A number of applications within statistics, decision theory, and signal processing are suggested, and a numerical example illustrating the capabilities of the elaborated network is given.

Worst-case traversal time modelling of Ethernet based in-car networks using real time calculus

The paper addresses performance modelling of safety critical Ethernet networks with special attention to in-car networks. A specific Ethernet/IP based in-car network is considered as use-case. The modelling is based on the analytical method Real-Time Calculus (RTC), providing hard bounds on delay and buffer utilization. We show how RTC can be applied on the use-case network. Furthermore, we develop a network simulation, used to evaluate the overestimation. It is found that the delays from RTC is significantly overestimated. The bounds from RTC, however, are guaranteed bounds, which is not the case for the simulated.

Potentially Distributable Energy: Towards Energy Autonomy in Large Population of Mobile Robots

We propose a new concept, potentially distributable energy, in the field of autonomous mobile robots. Considering a system of multiple robots powered by batteries, each robot no longer works since its energy capacity is expired. To extend operating time, the robot needs to replenish energy through recharging energy. To date, except research on vaccum cleaning robots that are able to recharge battery when docking with the fixed station has been achieved, there does not exist any research of energy distribution to prolong operating time in a large population of mobile robots. This could be caused by the lack of using rechargeable battery in the fact that the robot has to normally spend the charging-time much longer than the operating time. This paper presents simulation results of mobile robots that are capable of not only self-recharging energy but also exchanging batteries to the other robots. Initially, we describe a simulation of multiple mobile robots, and then issue rules of battery exchange, which is formulated under constraints of workload, distance and remaining capacity. The simulation shows that: (a) a robot is able to be energetically autonomous if its energy can be replenished by the other robots or it is able to come back to the main charging station to replenish itself; (b) energy of a robot is always under constraints of energy distribution of the mother charging station and the other robots; (c) distributed energy balance is the main elements to decide a number of robots in a specific area and an ideal location of the repository when one wants to deploy a large population of autonomous mobile robots. Finally, based on results of the simulation we adjust rules for our real multirobot system.

Stochastic stability of systems with semi-Markovian switching

This paper examines stochastic stability of switched dynamics in continuous time. The time evolution of the so called continuous state is at all times, determined by the dynamics indexed by the switching process or discrete state. The main contribution of this paper appears as stochastic stability results for switched dynamics with semi-Markovian switching. The notion of moment stability in the wide sense (MSWS) is applied as a generalization of ? -moment stability. A sufficient criterion for MSWS is presented for the above class of systems, where each subsystem is assumed to be characterized by a Lyapunov function candidate together with an associated growth rate equation. For the set of Lyapunov functions, a compatibility criterion is assumed to be fulfilled, bounding the ratio between pairs of Lyapunov functions.

Being sociable: Multirobots with self-sustained energy

To date, mobile robots are emerging to target for applications in our life. Most of research focus on autonomous behaviors of mobile robots, instead of considering the determination to make a robot being truly autonomous. To be interested in animal species, e.g ant or bee, an individual has to coordinate with others to keep the society alive. Likewise, as an initial condition, a robot system is truly autonomous if such a system has energy autonomy. Further, to be sociable robots, the robots must have not only behavioural autonomy but energetic autonomy. Thereby, inspired from the nature of animals, this paper aims to present a system of multiple robots with self-sustained energy to achieve energy autonomy. We examine a multirobot system with energy sharing capability based on battery distribution to approach to the scope of sociable robots. First we show simulation results of the potential energy to suggest a scheme for creating sociable robots. Later we perform early real implementation of our robots in the CAD model, hardware, and the control architecture. Finally we describe the initial experimental deployment of the system.

Active fault diagnosis for hybrid systems based on sensitivity analysis and EKF

An active fault diagnosis (AFD) approach for different kinds of faults is proposed. The AFD approach excites the system by injecting a so-called excitation input. The input is designed off-line based on a sensitivity analysis in order that the maximum sensitivity for each individual system parameter is obtained. Using the maximum sensitivity results in better precision in the estimation of the corresponding parameter. The fault detection and isolation is done by comparing the nominal parameters with those estimated by an extended Kalman filter. In this study, Gaussian noise is used as the input disturbance as well as the measurement noise for simulation. This method is implemented on a large scale livestock hybrid ventilation model which was obtained during previous research.

An Approach to Sociable Robots through Self-distributed Energy

Research of autonomous mobile robots has mostly emphasized interaction and coordination that are naturally inspired from biological behavior of birds, insects, and fish: flocking, foraging, collecting, and sharing. However, most research has been only focused on autonomous behaviors in order to perform robots like animals, whereas it is lacked of determinant to those behaviours: energy. Approaching to cluster animal and the higher, collective and sharing food among individuals are major activity to keep society being. This paper issues an approach to sociable robots using self-maintained energy in cooperative mobile robots, which is dominantly inspired from swarm behavior of collecting and sharing food of honey-bee and ant. Autonomous mobile robots are usually equipped with a finite energy, thus they can operate in a finite time. To overcome the finitude, we describe practical deployment of mobile robots that are capable of carrying and exchanging fuel to other robots. Mechanism implementation including modular hardware and control architecture to demonstrate the capabilities of the approach is presented. Subsequently, the battery exchange algorithm basically based on probabilistic modeling of total energy on each robot located in its local vicinity is described. The paper is concluded with challenging works of chain of mobile robots, rescue, repair, and relation of heterogeneous robots

Stochastic Stability of Markovianly Switched Systems

This technical note examines the stochastic stability of noisy dynamics in discrete and continuous time. The notion of moment stability in the wide sense (MSWS) is presented as a generalization of ϵ-moment stability. MSWS is intentionally not based on stochastic convergence properties, since in most practically appearing systems convergence to any equilibrium is not present. A sufficient criterion for both MSWS and ergodicity is presented for a class of systems comprising a finite set of noisy dynamical systems among which switching is governed by a Markov chain. Stability/instability properties for each separate subsystem are assumed to be quantified by a Lyapunov function candidate together with an associated growth rate equation. For the set of Lyapunov functions, a compatibility criterion is assumed to be fulfilled, bounding the ratio between pairs of Lyapunov functions.