Experimental comparison between proportional and PWM-solenoid valves controlled servopneumatic positioning systems

The performance of the Dynamical Adaptive Backstepping-Sliding Mode Control (DAB-SMC) scheme for positioning of a pneumatic cylinder regulated by two types of PWM-solenoid valves is experimentally investigated. The goal is to study the compromise in controller’s performance as the system moves from using a proportional valve to employing the low-cost PWM-solenoid valves. Sinusoidal and multiple-step inputs are used as the reference position trajectories. Experimental results show that the DAB-SMC scheme works best with the proportional valve. The performance, however, deteriorates by more than twofold, once the system utilizes PWM- solenoid valves of 3/2-way or 2/2-way configurations. From this study, tradeoff between performances of different types of valves applied on a DAB-SMC scheme-controlled servo positioning system is successfully documented. This information helps to configure appropriate servopneumatic system for positioning applications

Drivers and Impacts of R&D Adoption on Transport and Logistics Services

Actually, technologies and applications in industries are changing via business restructuring, new business models, new knowledge and supply chains. So R&D is not focused primarily on manufacturing industry as it used to be, but on different kinds of industries as logistics and transport (TLS). Nevertheless, the characteristics of the TLS industry determine the introduction of specific R&D solutions accordingly to sectors operations. The objective of this paper is to describe the R&D opportunities in the TLS industry and how managers use them to make their businesses more innovative and efficient. Using the Structure-Conduct-Performance (SCP) model the paper identifies the links between R&D adoption and innovation dynamics. Relating the findings, on the driver’s side there are three points that are worth mentioning: increasing market competition, the relationships of firms interacting with each other and the availability and quality of complementary assets such as employee skills and IT know-how. On the impacts’ side, firms advanced in terms of implementing R&D solutions are more likely to implement organizational changes. Finally, a set of recommendations on how to further improve the continuous innovation in the TLS industry is presented