Using RGB-D sensors and evolutionary algorithms for the optimization of workstation layouts

[EN] RGB-D sensors can collect postural data in an automatized way. However, the application of these devices in real work environments requires overcoming problems such as lack of accuracy or body parts' occlusion. This work presents the use of RGB-D sensors and genetic algorithms for the optimization of workstation layouts. RGB-D sensors are used to capture workers' movements when they reach objects on workbenches. Collected data are then used to optimize workstation layout by means of genetic algorithms considering multiple ergonomic criteria. Results show that typical drawbacks of using RGB-D sensors for body tracking are not a problem for this application, and that the combination with intelligent algorithms can automatize the layout design process. The procedure described can be used to automatically suggest new layouts when workers or processes of production change, to adapt layouts to specific workers based on their ways to do the tasks, or to obtain layouts simultaneously optimized for several production processes.This work was supported by the Programa estatal de investigacion, desarrollo e innovacion orientada a los retos de la sociedad of the Government of Spain under Grant TIN2013-42504-R.Diego-Mas, JA.; Poveda Bautista, R.; Garzon-Leal, D. (2017). Using RGB-D sensors and evolutionary algorithms for the optimization of workstation layouts. Applied Ergonomics. 65:530-540. doi:10.1016/j.apergo.2017.01.012S5305406

Harmonic Minimization in a Three-phase Asymmetrical PWM Rectifier

- A new pulse-width modulation (PWM) method for a three-phase bridge rectifier developed here gives minimized low order harmonics. As a PWM rectifier, it offers better input and output characteristics than phase-controlled rectifiers. It has inherited the chmcteristics of the PWM rectifier such as having high power factor at the input with low harmonic content of the input current and zero phase-shift of input voltage and current. The availability of power transistors at high power ratings enabled the implementation of PWM rectifiers much easily. The modulation method is applied to a dc-motor drive system at 1kW rating. A high speed micro-controller produces the switching pulses