Marcelo Henrique Souza Bomfim, Eduardo José Lima II, Neemias Silva Monteiro and Vinícius Avelino Sena
This paper aims to present a new approach, called hybrid model reference adaptive controller or H-MRAC, for the hybrid controller (proportional-integral-derivative [PID + MRAC]…
Abstract
Purpose
This paper aims to present a new approach, called hybrid model reference adaptive controller or H-MRAC, for the hybrid controller (proportional-integral-derivative [PID + MRAC]) that will be used to control the position of a pneumatic manipulator.
Design/methodology/approach
It was developed a McKibben muscle using nautical mesh, latex and high-density polyethene connectors and it was constructed an elbow manipulator with two degrees of freedom, driven by these muscles. Then it was presented the H-MRAC control law based on the phenomenological characteristics of the plant, aiming at fast response and low damping. Lyapunov's theory was used as the project methodology, which ensures asymptotic stability for the control system.
Findings
It was developed a precise control system for a pneumatic manipulator and the results were compared to previous research.
Research limitations/implications
In collaborative robotics, human and machine occupy the same workspace. This research promotes the development of safer and more complacent mechatronic systems in the event of collisions.
Practical implications
As a practical implication, the research allows the substitution of electric motors by McKibben muscles in industrial robots with high accuracy.
Social implications
The pneumatic manipulator will make the human-robot physical interaction safer as it can prevent catastrophic collisions causing victims or equipment breakdown.
Originality/value
When compared to results in the literature, the present research showed a 37.51% and 36.74% lower global error in position tracking than MRAC and Adaptive proportional-integral-derivative (A-PID), respectively, validating its effectiveness.
Details
Keywords
Barbara de Lima Voss, David Bernard Carter and Bruno Meirelles Salotti
We present a critical literature review debating Brazilian research on social and environmental accounting (SEA). The aim of this study is to understand the role of politics in…
Abstract
We present a critical literature review debating Brazilian research on social and environmental accounting (SEA). The aim of this study is to understand the role of politics in the construction of hegemonies in SEA research in Brazil. In particular, we examine the role of hegemony in relation to the co-option of SEA literature and sustainability in the Brazilian context by the logic of development for economic growth in emerging economies. The methodological approach adopts a post-structural perspective that reflects Laclau and Mouffe’s discourse theory. The study employs a hermeneutical, rhetorical approach to understand and classify 352 Brazilian research articles on SEA. We employ Brown and Fraser’s (2006) categorizations of SEA literature to help in our analysis: the business case, the stakeholder–accountability approach, and the critical case. We argue that the business case is prominent in Brazilian studies. Second-stage analysis suggests that the major themes under discussion include measurement, consulting, and descriptive approach. We argue that these themes illustrate the degree of influence of the hegemonic politics relevant to emerging economics, as these themes predominantly concern economic growth and a capitalist context. This paper discusses trends and practices in the Brazilian literature on SEA and argues that the focus means that SEA avoids critical debates of the role of capitalist logics in an emerging economy concerning sustainability. We urge the Brazilian academy to understand the implications of its reifying agenda and engage, counter-hegemonically, in a social and political agenda beyond the hegemonic support of a particular set of capitalist interests.