Time-Optimal Velocity Tracking Control for Consensus Formation of Multiple Nonholonomic Mobile Robots

The problem of velocity tracking is considered essential in the consensus of multi-wheeled mobile robot systems to minimise the total operating time and enhance the system’s energy efficiency. This study presents a novel switched-system approach, consisting of bang-bang control and consensus formation algorithms, to address the problem of time-optimal velocity tracking of multiple wheeled mobile robots with nonholonomic constraints. This effort aims to achieve the desired velocity formation in the least time for any initial velocity conditions in a multiple mobile robot system. The main findings of this study are as follows: (i) by deriving the equation of motion along the specified path, the motor’s extremal conditions for a time-optimal trajectory are introduced; (ii) utilising a general consensus formation algorithm, the desired velocity formation is achieved; (iii) applying the Pontryagin Maximum Principle, the new switching formation matrix of weights is obtained. Using this new switching matrix of weights guarantees that at least one of the system’s motors, of either the followers or the leader, reaches its maximum or minimum value by using extremals, which enables the multi-robot system to reach the velocity formation in the least time. The proposed approach is verified in a theoretical analysis along with the numerical simulation process. The simulation results demonstrated that using the proposed switched system, the time-optimal consensus algorithm behaved very well in the networks with different numbers of robots and different topology conditions. The required time for the consensus formation is dramatically reduced, which is very promising. The findings of this work could be extended to and beneficial for any multi-wheeled mobile robot system.

The structure of scientific controversies: Thomas Kuhn’s social epistemology

Changes of theories are major events in science. Two main types of questions may be asked about them: i) how do scientists choose new theories?, and ii) how is consensus formed? Generally, philosophers do not distinguish these two questions. Kuhn, on the contrary, offers very different answers to each of these questions. Theory-choice, on the one hand, is explained through the application of epistemic criteria, such as accuracy and consistency; nonetheless, because these values do not prescribe a single choice, consensus formation, on the other hand, is explained through a series of socio-epistemic mechanisms, namely: scientific pedagogy, diffusion and production of knowledge within the community (the “wave motion”), and restructuring of the scientific field. These mechanisms are the basis of Kuhn’s social epistemology, in that they are not restricted to sociology nor epistemology, encompassing both social interactions and epistemic evaluations of theories. Keywords: Thomas Kuhn, consensus formation, social epistemology.

Strategy consensus and social practice: a perspective from public sector managers

PurposeThe purpose of this paper is to investigate consensus formation among the top and middle managers during the strategy process. Specifically, the paper seeks to gain insight into the role of strategic consensus during the transition between strategy formulation and implementation.Design/methodology/approachAdopting a social practice perspective and a single case study approach, we undertook semi-structured interviews of twenty-seven managers working in a Kuwaiti Ministry. Data collected were analyzed using thematic analysis.FindingsWe found that social interaction among individuals with similar characteristics and shared understanding fosters consensus. Factors such as alignment of strategic priorities, managerial flux and centralized control contribute to the extent to which strategic consensus is achievable. Additionally, managerial turnover and lack of empowerment hamper the development of shared understanding. Finally, that consensus on strategy content is insufficient for effective intergroup communications.Originality/valueThe research contributes to the strategic consensus literature from a social practice perspective as it provides new insights into the dynamics between top managers and middle managers. Significantly, it highlights the importance and need for common understanding, as well as communications prioritization among managers for consensus development and successful implementation of organization strategy.

Sceptic priors and climate consensus

How much evidence would it take to convince sceptics that they are wrong about climate change? I explore this question within a Bayesian framework. I consider a group of stylised sceptics and examine how these individuals update their beliefs in the face of current and continuing climate change. I find that available evidence in the form of instrumental climate data tends to overwhelm all but the most extreme priors. Most sceptics form up dated beliefs about climate sensitivity that correspond closely to estimates from the scientific literature. However, belief convergence is a non-linear function of prior strength. It thus becomes increasingly difficult to convince the remaining pool of sceptics. I discuss necessary conditions for consensus formation under Bayesian learning and show how apparent deviations from the Bayesian ideal still be accommodated within the same conceptual framework. I argue that a generalized Bayesian model thus provides a bridge between competing theories of climate scepticism as a social phenomenon.

Attempt to Develop High-Value Rice in the Shimojin District, Mashiki Town, Kumamoto Prefecture: Transition Into Sustainable Local Community Using Disaster Recovery from the 2016 Kumamoto Earthquakes as a Branding Strategy

In this chapter, we report the case of a co-design project undertaken in the Shimojin district that was severely damaged by the 2016 Kumamoto Earthquakes. We, IDS3, and local residents have not only attempted to recover the aforementioned district from the damages it suffered due to the earthquakes but also unite its entire community, which is currently suffering from population decline and aging. To supplement its local agriculture, we initiated the co-design project as a means to promote rice branding by adding value by utilizing the biodiversity in the district and transforming the district’s rice paddy fields into eco-friendly paddy systems. We were involved with the project since the consensus building phase owing to our co-design experience with regard to restoration planning at disaster restoration sites and knowledge about the district. We primarily conducted our research in three fields: (1) design of the recovery plan of eco-friendly paddy fields and agricultural ditches, (2) consensus formation for rice branding, (3) exploration of eco-friendly farming method suitable for the region under study.