Virtual sensing is crucial in order to provide feasible and economical alternatives when physical measuring instruments are not available. Developing model-based virtual sensors to calculate real-time information at each targeted location is a complex endeavor in terms of sensing technology. This paper proposes a new approach for model-based virtual sensor development using computational fluid dynamics (CFD) and control. Its main objective is to develop a three-dimensional (3D) real-time simulator using virtual sensors to monitor the temperature in a greenhouse. To conduct this study, a small-scale greenhouse was designed, modeled, and fabricated. The controller was based on the convection heat transfer equation under specific assumptions and conditions. To determine the temperature distribution in the greenhouse, a CFD analysis was conducted. Only one well-calibrated and controlled physical sensor (temperature reference) was enough for the CFD analysis. After processing the result that was obtained from the real sensor output, each virtual sensor had learned the associative transfer function that estimated the output from given input data, resulting in a 3D real-time simulator. This study has demonstrated, for the first time, that CFD analysis and a control strategy can be combined to obtain system models for monitoring the temperature in greenhouses. These findings suggest that, generally, virtual sensing can be applied in large greenhouses for monitoring the temperature using a 3D real-time simulator.

The use of specialized devices, such as orthopedic devices, has become indispensable in the lives of people with disabilities since ancient times. The primary purpose of such devices is to perform activities and solve problems that afflict their bearers in any extremity of their body. One of the most recurrent problems occurs in the lower extremities regarding mobility and autonomy. In addition, the use of orthopedic devices is considered a tool to lighten the repetitive and heavy rehabilitation work of physiotherapists while improving the patient’s recovery efficiency. A significant challenge is that a great variety of these devices are similar in their design and manufacture, complicating their application in rehabilitation processes. For these reasons, this article aims to provide an overview of the features and considerations made in the architecture of orthosis designs, emphasizing lower extremity orthoses for the case of knee joint analysis. A literature review of active and passive knee orthoses manufactured from the 1970s to the present was carried out, considering aspects such as manufacturing materials, mechanical systems, types of actuators, and control strategies. This review shows that the designs and development of orthoses have been abundant in these devices for lower limbs. Based on the literature collected, we have studied the main robotic devices focusing on the characteristics of design, manufacturing, and control systems to assist in human locomotion and support in rehabilitation processes.

Hydroponics is crucial for providing feasible and economical alternatives when soils are not available for conventional farming. Scholars have raised questions regarding the ideal nutrient solution flow rate to increase the weight and height of hydroponic crops. This paper presents the turbulent kinetic energy distribution of the nutrient solution flow in a nutrient film technique (NFT) hydroponic system using the computational fluid dynamics (CFD) method. Its main objective is to determine the dynamics of nutrient solution flow. To conduct this study, a virtual NFT hydroponic system was modeled. To determine the turbulent kinetic energy distribution in the virtual NFT hydroponic system, we conducted a CFD analysis with different pipe diameters (3.5, 9.5, and 15.5 mm) and flow rates (0.75, 1.5, 3, and 6 L min⁻¹). The simulation results indicate that different pipe diameters and flow rates in NFT hydroponic systems vary the turbulent kinetic energy distribution of nutrient solution flow around plastic mesh pots.

Continuous passive motion (CPM) machines are used in the rehabilitation of members that have been injured to recover their range of motion and prevent stiffness. Nowadays, some CPM machines for the knee, ankle, arm, and elbow are available commercially. In this paper, ankle and shoulder rehabilitation robots, based on an X-Y table, are presented. The novelty of these rehabilitation robots is that they have a computerized numerical control system, resulting in low-cost machines. Some G-codes for basic and combined movement routines for ankle and shoulder rehabilitation are presented. In addition, the use of a robust generalized PI controller is also proposed to guarantee safe rehabilitation movements and compensate for passive stiffness in the ankle joint of stroke survivors. Some numerical simulations are included to illustrate the dynamic performance of the robust Generalized Proportional Integral (GPI) controller using the virtual prototype.

Nowadays, the use of biomechanical devices in medical processes and industrial applications allows us to perform tasks in a simpler and faster way. In the medical field, these devices are becoming more and more common, especially in therapeutic applications. In the design and development of orthopedic devices, it is essential to consider the limbs’ kinematic, kinetic, and anthropometric conditions, as well as the implementation of control strategies (robust, PID, fuzzy, and impedance, among others). This work presents a virtual prototype of a knee orthosis and the implementation of a control system to follow a desired trajectory. Results are presented with the virtual prototype through a co-simulation between MSC Adams and MATLAB Simulink with fuzzy control, virtually replicating the gait cycle.