STEP-NC-Compliant Implementation to Support Mixed-Control Technologies Applied to Stone-Processing Machines Based on Industrial Automation Standards

STEP-NC (Standard for the Exchange of Product Model Data–Numerical Control) for metal milling and turning is not implemented by industrial computer numerical controllers. Solutions reported are prototypes based on post-processing in G-code. Moreover, minority machining processes, such as stone cutting, have not yet been contemplated in the STEP-NC standard. This article takes that sector as a use case. An extended STEP-NC model for circular saw stone-cutting operations is proposed, and a prototype automation implementation is developed to work with this extended model. This article shows how modern technological resources for coordinated axes control provided by many industrial controllers for the automation of general-purpose machines can speed up the processes of implementing STEP-NC numerical controllers. This article proposes a mixed and flexible approach for STEP-NC-based machine automation, where different strategies can coexist when it comes to executing STEP-NC machining files, so controllers do not need to implement the standard in an exhaustive way for all the possible features, but only at selected ones when convenient. This is demonstrated in a prototype implementation which is able to process STEP-NC product files with mixed-feature types: standard milling and non-standard sawblade features for stone processing.

Evaluation of the Kinetic of Cu2+ Adsorption in the PVA Membranes Crosslinked with Sulfosuccinic and Citric Acids

Membrane of Poly (vinyl alcohol) (PVA) crosslinked with sulfosuccinic acid (SSA) and citric acid (CA) were characterized for the adsorption of copper ions (Cu2+). Usually the membranes used for this application have inorganic materials in their structure. However, when using only these acids, it was verified that the membrane containing SSA presents less swelling than the PVA and absorbs a higher content of Cu2+ when compared to the membrane containing CA. Therefore, it can be assumed that the membrane containing SSA can be used to cover soils that need protection against this type of ion. leaching. Kinetic models of diffusional and chemical control were used to understand the interaction phenomena of adsorption of ions and membranes. The mixed control kinetic model was also evaluated, in which it was possible to evaluate different parameters regarding the interaction ions and membranes. The obtained results indicated that the developed process has relevant utility. The kinetic modeling results contribute to a better understanding of heating phenomena of adsorption and also to the development of new cleaner technologies.

Integrated DYC and ASR Mixed Control of Distributed Drive Electric Vehicle Using Co-Simulation Methodology

The improvement of handling and stability performance of distributed drive electric vehicle (DDEV) is analyzed, visualized and designed by proposing and deploying the mixed control strategies in this paper including Direct Yaw Control (DYC), Anti-slip Regulation (ASR) and dual-mode switching control. The practicability and real time visualization of driving efficiency and timeliness of DDEV is achieved to reduce the margin of error for the desired torque value by employing the DYC strategy which uses fuzzy PID algorithm. Furthermore the ASR strategy which adopts the optimal slip rate algorithm to determine the requirement of desired torque value based on the different road conditions is used to reduce slip phenomenon effectively and to maintain handling control of DDEV. In response to different scenes especially conflict and coexistence between DYC and ASR, the dual-mode switching control strategy is applied to find more suitable slip rate range by using the root mean square error method (REME). Finally, co-simulation platform of ADAMS/Car and MATLAB/Simulink is built to simulate the mixed control strategies by integrating dual-mode switching control, DYC and ASR. The simulation results show that this strategy has a more significant control effect needed to meet the requirements of normal vehicle handling and stability. The mixed control strategy is adopted and downloaded into the electronic control unit of our student type formula vehicle called Flash V6 which was designed and developed by a team of students, the ZUST ATTACKER Team.

Dealing with measurement error in list experiments: Choosing the right control list design

List experiments are widely used in the social sciences to elicit truthful responses to sensitive questions. Yet, the research design commonly suffers from the problem of measurement error in the form of non-strategic respondent error, where some inattentive participants might provide random responses. This type of error can result in severely biased estimates. A recently proposed solution is the use of a necessarily false placebo item to equalize the length of the treatment and control lists in order to alleviate concerns about respondent error. In this paper we show theoretically that placebo items do not in general eliminate bias caused by non-strategic respondent error. We introduce a new option, the mixed control list, and show how researchers can choose between different control list designs to minimize the problems caused by inattentive respondents. We provide researchers with practical guidance to think carefully about the bias that inattentive respondents might cause in a given application of the list experiment. We also report results from a large novel list experiment fielded to over 4900 respondents, specifically designed to illustrate our theoretical argument and recommendations.