The switching action of the main circuit breaker of the train will produce switching overvoltage. In order to suppress the switching overvoltage, the phase selection control of the circuit breaker is required. However, the mechanical structure of the train-mounted electronically controlled pneumatic vacuum main circuit breaker is too complicated, resulting in a large dispersion of its closing action time, which is not suitable for the traditional phase selection control system. In order to obtain the accurate closing action time, a method for predicting the closing action time of train electronically controlled pneumatic vacuum main circuit breaker based on the PCA and GBDT algorithm is proposed. The relationship between the closing phase of AC25 kV power supply train and the peak value of switching overvoltage is obtained by simulation and field test, and the accuracy requirement of the prediction model is determined, that is, the prediction error should be within ±3.3 ms. The final prediction results show that the prediction error of the on-board electronically controlled pneumatic vacuum main circuit breaker closing action time prediction model based on the PCA and GBDT algorithm is controlled within ±3.3 ms, and the probability is 92%, which meets the accuracy requirements of phase selection control.

This study presents the development of a prototype anthropomorphic soft robotic gripper intended for applications in rehabilitation and assistive robotics, where safe and adaptive interaction with humans is required. The device consists of three elastomeric fingers, fabricated in TPU via FFF 3D printing and actuated through pneumatic soft actuators that ensure compliant contact with both biological tissue and rigid objects. A custom 3D-printed pneumatic rotary actuator enables finger reconfiguration, thereby extending the range of grasping modalities. The actuation system comprises six 2/2 solenoid valves controlled by an Arduino Uno and integrated into a dedicated pneumatic circuit. Experimental characterization demonstrated a peak grasping force exceeding 17 N on rigid targets, while functional tests in table-picking scenarios confirmed adaptability to objects of varying shapes and sizes. Owing to its anthropomorphic configuration, mechanical compliance, and ease of fabrication and control, the proposed gripper represents a versatile solution for rehabilitation-oriented devices as well as assistive robotic end-effectors in pick-and-place tasks.

Actuators are an essential part of a robot, creating movement between the robot and its environment. Actuators with thin and flexible shapes can operate in a wider variety of environments, and actuators with multiple degrees of freedom can generate more complex movements. Here, we propose a soft pneumatic actuator in the form of a thin, flexible sheet that can generate different motion vector fields on its surface. The actuator contains dozens of thin pneumatic chambers and multi-channel pneumatic circuits connecting them in its thin body, converting input pressure into complex surface movements. Depending on the pressure sequence, it can produce surface movements in six different directions, at different speeds, and over different distances. The versatility of the proposed actuator is demonstrated through tasks such as obstacle removal in narrow pipes, in-hand manipulation, and underwater object transport.

Regulating Airflow Using Hybrid LCN for Soft Pneumatic Circuits

This study provides a set of designs, simulations and experiments for developing an actuating method for manual pipettes. The goal is to enable robotic manipulation and automatic pipetting, while using manual pipetting devices. This automation is designed to be used as a flexible alternative tool in small and medium-sized biochemistry laboratories that do not possess proper automated pipetting technology, in order to relieve the lab technicians from the tedious, repetitive and error-prone process of manual pipetting needed for the preparation of biological samples. The selected approach is to use a set of pressure-controlled pneumatic cylinders in order to control the actuation and force of the pipettes’ manual buttons. This paper presents a mechanical design, analysis, pneumatic simulation and functional robotic simulation of the developed device, and a comparison of possible pneumatic solutions is presented to explain the selected actuation method. Remote pneumatic pressure sensing is employed in order to avoid electrical sensors, connectors and wires in the area of the actuators, thus expanding the possibility of working in some electromagnetic-compatible environments and to simplify the connecting and cleaning process of the entire device. A functional simulation is conducted using a combination of software packages: Fluidsim for pneumatic simulation, URSim for robot programming and CoppeliaSim for application integration and visualization. Experimental validation is conducted using off-the-shelf pneumatic components, assembled with 3D-printed parts and mounted onto an existing pneumatic gripper. This complete assembly is attached to an industrial collaborative robot, as an end effector, and a program is written to test and validate the functions of the complete device. The in-process actuators’ working pressure is recorded and analyzed to determine the suitability of the proposed method and pipetting ability. Supplemental digital data are provided in the form of pneumatic circuit diagrams, a robot program, simulation scene and recorded values, to facilitate experimental replication and further development.

Being flexible and adaptive to various environments, soft robotics shows promise as a more robust alternative in many applications compared to traditional, rigid robotics. Of many employable different actuation strategies, pneumatically driven soft robotics have gained attraction owing to their relative straightforward manufacturing and capability to produce significant force to their environment upon interaction. To enable more autonomous pneumatic systems, however, there is an emerging need for developing smarter fluidic elements responding to environmental cues, to provide embodied control and regulation. Herein, a liquid crystal network (LCN)‐based fluid regulator is designed to impart stimuli responsiveness and regulation into fluidic circuits by combining radially aligned nematic and nonaligned isotropic LCNs. Assisted by a finite element method, the thermoresponsiveness of the LCN is discussed. Finally, the regulating behavior of the responsive pneumatic regulator is demonstrated, which alters its fluidic resistance with changing temperature. This work emphasizes the potential of advancing responsive soft robotics that can interact with their environment through multiphysical stimuli.

This paper presents a new computational library for pneumatic circuits, written in the specialized circuit-oriented language “Modelica”, and executed within an open-source IDE, “OpenModelica”, freely available for downloading on the Internet. The library focuses on the problem of energy efficiency and energy savings (two different concepts, that we intend to clarify in the text). The idea is to use the Modelica scripts to simulate typical circuits, known by their energy-efficient designs. We reason that air throttling within valves is one of the great challenges when it comes to energy losses. Also, we argue that compressed air reuse can be seen as a means of increasing efficiency, basically through replacing air throttling with counter-pressure velocity control. A simplified version of the developed Modelica library is made available to the reader in the Appendix A, to be used with new scripts and adapted to different realities. In our view, in many situations, open-code Modelica programs may constitute an alternative to proprietary software, where the mathematical models of components are mostly hidden from the end user. Theoretical experiments are carried out, focusing on energy management. The results show that the Modelica library hereby presented is solid, with great prospects of future development. They also show that energy efficiency in pneumatic circuits, at times, comes with the cost of poorly controlled velocity and pressure at the actuator, which requires a careful analysis by the designer, before an actual implementation.

The escalating volume of plastic waste has become a critical environmental challenge, highlighting the need for innovative solutions to repurpose it into valuable construction materials. This study aimed to design and develop a pneumatic-based eco-paving block printing machine that uses plastic waste as its primary raw material. The research methodology encompassed the design and simulation of pneumatic circuits, structural analysis involving stress distribution, displacement, and factor of safety (FOS), and strength testing of the fabricated eco-paving blocks. The machine was equipped with a pneumatic cylinder measuring 80 × 75 mm, operating at a pressure of 6 bar and generating a maximum pressing force of 300 kg. The simulation results confirmed that the maximum stress and displacement remained within safe limits, with a minimum FOS of 8.4, thereby ensuring a stable and reliable design. Testing of the eco-paving blocks revealed compressive strengths ranging from 38 to 54 MPa, surpassing the requirements of the SNI 03-0691-1996 standard. This study demonstrates that a pneumatic-based eco-paving block printing machine effectively transforms plastic waste into high-quality construction materials compliant with national standards, offering a practical solution to the plastic waste crisis while promoting sustainability in the construction industry.

Animals and robots employ central pattern generators, networks that invoke rhythmic patterns from constant inputs, to orchestrate limb movements during locomotion. Artificial central pattern generators (CPGs) can be either implemented in software or constructed in a physical domain. The former lacks embodiment, inhibiting direct interactions with the physical world. The latter is restricted by a complex translation of abstract functions to the physical domain, e.g., negative feedback, if‐then behavior, etc. Here, self‐oscillators, a rudimentary type of central pattern generators, that find ground in both the pneumatic and electrical domains are demonstrated. First, the hysteretic behavior of previously developed conical membranes is analyzed in deformation space. This state‐space behavior is then transformed to the electrical domain by means of a stretchable strain sensor. Next, an analog comparator distinguishes between the two states and instructs a pneumatic solenoid valve to counteract the current state. As a result, a stable oscillation emerges, with a frequency that is dominated by the physical characteristic of the pneumatic circuit. As such, the proposed electropneumatic oscillator provides a promising platform for building complex CPGs that control interactive neuromorphic robots.

The teaching of automation and control technologies requires laboratories equipped with didactic benches, making the teaching-learning process costly and limited in terms of accessibility. Virtual benches offer an option for face-to-face teaching, democratizing access to education, including in remote locations such as rural areas. The SIMP virtual bench is a free software developed at the Industrial Technical College of Santa Maria (CTISM) in conjunction with the Federal University of Santa Maria (UFSM), being a low-cost and fast-learning option. Through experimentation, it was found that students have a much higher success rate correctly assembling pneumatic circuits when using the software compared to using only the physical bench (76% vs. 24%). The virtual bench, in conjunction with the physical bench through the Digital Twin approach enhances the accessibility and effectiveness of education in pneumatics. This article explores the possibility of applying SIMP as a Digital Twin of a pneumatic didactic bench by replicating its behavior, becoming an appropriate option for the Brazilian educational reality, with the objective of improving teaching and learning in the area of industrial automation in line with the principles of Industry 4.0.

The aim of this article is to present an educational model of the process of teaching students in subjects focused on the use of compressed air in automated industrial operations. The starting point is the existing commercially available training platform kit, the use of which provided the basis for developing the student training model described in the article. The article further discusses the training needs in all methods of controlling pneumatic circuits and focuses on the possibility of building an independent training workplace based on the electropneumatic base of the components used. The article describes several stages of the constantly improved educational platform, also with the contribution of student involvement in this activity. The conclusions of the article offer further guidance in the gradual completion of the educational model focused mainly on the practical training of graduates resulting in the ability to respond to market challenges after completing their university studies at our faculty.

Modern industrial and medical applications require soft actuators with practical actuation methods, capable of precision control and high-speed performance. Within the realm of medical robotics, precision and speed imply less complications and reduced operational times. Soft fluidic actuators (SFAs) are promising candidates to replace the current rigid endoscopes due to their mechanical compliance, which offers safer human-robot interaction. However, the most common techniques used to operate SFAs, pneumatics, and hydraulics present limitations that affect their performance. To reduce manufacturing complexity, enhance response time, improve control precision, and augment the usability of SFAs, we propose a Pneudraulic Actuation (PHA) system that, for the first time, combines a pneumatic and hydraulic circuit in series. To examine this proposal, a comparative assessment of the proposed actuation technique with the common techniques was carried out, in terms of bending performance and generation of audible noise level during functioning. The analysis provides insights into the performance of various fluidic actuation methods for SFAs, highlighting significant effects related to fluid-structure interactions and the presence of trapped air. Thereafter, a comparative assessment of different fluidic circuits is performed, illustrating how tubing length, inner and outer diameter, as well as the amount of different fluidic medium impact the dynamic behavior of the system, amplifying the importance of fluid mechanics for design optimization. Furthermore, we propose a model-based control strategy that solely focuses on fluid dynamics, utilizing the hydraulic-electric analogy and the resistor-inductor-capacitor circuit theory. Our PID controller improved actuation speed by 52.63% and reduced audible noise by 17.17%.

To address the challenges of labor-intensive, inefficient, and inconsistent manual hole sowing and transplanting of Angelica sinensis in rain-fed hilly regions of Northwest China, a pneumatic hole-sowing device was designed based on the principle of electromagnetically controlled, high-speed reciprocating cylinder motion. Considering the agronomic requirements for transplanting mulched Angelica sinensis, the device’s structure and operational parameters were optimized. The key mechanisms involved in hole sowing and seedling placement were analyzed. A pneumatic circuit system, controlled by a relay circuit, was established, and a hole-sowing mechanism with a delayed closure effect was designed. Using the Discrete Element Method (DEM) and Multi-Body Dynamics (MBD) coupling technology, a simulation of the hole-sowing process was conducted to evaluate the device’s performance and its impact on soil disturbance and hole reformation in the seedbed. Prototype device performance tests were conducted, using qualified seeding depth under mulch and hole spacing as indicators. When the theoretical hole spacing was 30 cm and the hole-sowing frequency was 60 plants/(min·row), the soil bin test results indicated a seeding depth qualification rate of 93%, a misalignment rate of 3%, and a spacing qualification rate of 83%; the field test results showed a qualified seeding depth rate under mulch of 96%, the hole misalignment rate was 5%, and the spacing qualified rate was 86%. The pneumatic hole-sowing device’s performance meets the agronomic requirements for vertical transplanting of Angelica sinensis seedlings. This research can serve as a reference for designing planting machinery for rhizomatous medicinal plants.

The purpose of the article is an in-depth study of ways to improve hydraulic and pneumatic systems using seven-line distributors. The main advantages focused on include increased efficiency, increased ease of installation, reduced hardware costs, and lower cost of the hydropneumatic actuator, these are the main components that must be guided when designing hydraulic and pneumatic circuits. When achieving these indicators, the hydraulic equipment used in the system plays an important role. Due to the idea of using extremely universal modules, the article investigated distributors with more lines than in standard solutions, namely seven-line hydraulic and pneumatic distributors. The conventional notation of the seven-line distributor is given. The minimal combinations of functions that can be implemented using seven-linear distributors are considered. It was determined what can be considered a trigger. Examples of the use of seven-line dividers in the construction of flip-flops with a dominant zero and flip-flops with a counting input are given. A detailed description of the operation of such triggers is given. The possibility of expanding the functions of the command apparatus was investigated. A detailed description of the command apparatus built on seven-line distributors is made. The definition of the concept of graph of operations is given. A graph of operations for a molding machine is built. On the basis of this graph, logical equations are constructed that describe the entire system operation process and transition states, taking into account the signals that move the system to the next state and the signals acting inside the transition. A pneumatic circuit for the molding machine was also constructed based on the obtained logic equations. A seven-line command apparatus was used to build this scheme, which demonstrates the possibilities of using a seven-line command apparatus in practical conditions. The areas of application of such command apparatus and seven-line distributors are considered.

Elbow joint rehabilitation presents a formidable challenge, underscored by the joint's complex biomechanics and high vulnerability to injuries and degenerative conditions. Despite the advancements in rehabilitative technology, current solutions such as rigid exoskeletons often fall short in providing the precision, flexibility, and customization needed for effective treatment. Although traditional robotic aids, such as rigid exoskeletons, help recover, they lack in providing sufficient flexibility, comfort, and easy customization with no need for complicated calculation and complex design considerations. The introduction of soft pneumatic muscles marks a significant development in the rehabilitation technologies field, offering distinct advantages and unique challenges when compared to conventional rigid systems. These flexible actuators closely mimic the elasticity of biological tissues, improving safety and interaction between humans and machines. Designed for individualized therapy, its versatility allows application in various rehabilitation scenarios, from clinical settings to home settings. The novelty of this approach lies in the development of biomechanically-compliant soft pneumatic muscles optimized for precise rotational control of the elbow joint, coupled with an advanced deep learning-based motion tracking system. This design overcomes limitations in force control, stability, and pressure requirements found in existing pneumatic-based systems, improving the safety and efficacy of elbow rehabilitation. In this study, the design, fabrication and systematic evaluation of a soft pneumatic muscle for elbow rehabilitation are presented. The device is designed to closely simulate the complex biomechanical movements of the elbow, with a primary focus on the rotational motions that are essential for controlling flexion and extension, as well as positioning the wrist during grasping tasks. Through the integration of precise geometric parameters, the actuator is capable of controlled flexion and extension, reflecting the natural kinematics of the elbow. Employing a rigorous methodology, the research integrates finite element analysis with empirical testing to refine the actuator's performance. Under varying air pressures, the soft muscle demonstrated remarkable deformation along the X-axis (10-150mm) and the Y-axis, indicative of its symmetrical rotational behavior, while maintaining minimal elongation along the Z-axis (0.003mm max), and proper lifiting force under a maximum wight of 470gm. highlighting the stability and targeted response of the device to pneumatic actuation. A specialized experimental apparatus comprising a 3D environment, a pneumatic circuit, a LabVIEW-based control system, and a deep learning algorithm was developed for accurate position estimation. The algorithm achieved a high predictive accuracy of 99.8% in spatial coordination tracking, indicating the precision of the system in monitoring and controlling the actuator's motion.

Pneumatic tactile displays dynamically customize surface morphological features with reconfigurable arrays of independently addressable actuators. However, their ability to render detailed tactile patterns or fine textures is limited by the low spatial resolution. For pneumatic tactile displays, the high-density integration of pneumatic actuators within a small space (fingertip) poses a significant challenge in terms of pneumatic circuit wiring. In contrast to the structure with a single-layer layout of pipes, we propose a multi-layered stacked microfluidic pipe structure that allows for a higher density of actuators and retains their independent actuation capabilities. Based on the proposed structure, we developed a soft microfluidic tactile display with a spatial resolution of 1.25 mm. The device consists of a 5 × 5 array of independently addressable microactuators, driven by pneumatic pressure, each of which enables independent actuation of the surface film and continuous control of the height. At a relative pressure of 1000 mbar, the actuator produced a perceptible out-of-plane deformation of 0.145 mm and a force of 17.7 mN. User studies showed that subjects can easily distinguish eight tactile patterns with 96% accuracy.

With the rapid development of pneumatic technology, there has been an increasing focus on leveraging pneumatic manipulator equipment that offers a blend of affordability, high performance, and numerous advantages, catering to the diverse needs of modern production practices. Pneumatic manipulators stand out among controlled manipulators due to their cost-effectiveness, straightforward design, impressive power-to-volume ratio, environmentally friendly operation, and robust resilience to external interference. This paper delves into addressing significant control deviations encountered during the dynamic movement of pneumatic manipulators, aiming to optimize the manipulator s structure and devise an efficient pneumatic system circuit. Additionally, it harnesses PLC control technology to devise a comprehensive control ladder diagram for the pneumatic manipulator, thereby ensuring precise control over its motion. By validating the feasibility and accuracy of the designed motion control methods, this study contributes to enhancing the overall efficiency and reliability of pneumatic manipulator systems in industrial settings.

Electromagnetic actuators, characterized by their lack of pneumatic or hydraulic circuits, rapid response, and ease of control, have the potential to significantly enhance the dynamic performance of automotive active suspensions. However, the complexity associated with their models and the calibration of control parameters hampers the efficiency of control design. To address this issue, this paper proposes a reinforcement learning vibration control strategy for electromagnetic active suspension. Firstly, a half-car dynamic model with electromagnetic active suspension is established. Considering the unknown dynamics of the actuator and its preset convergence performance, an optimal control method based on reinforcement learning is investigated. Secondly, a heuristic PI adaptive dynamic programming algorithm is presented. This method can update to the optimal control solution without requiring model parameters or initial design parameters. Finally, the energy consumption and dynamic performance of this method are analyzed through rapid prototyping control simulation. The results show that the ride comfort of the vehicle suspension can be improved with the given preset convergence rate.

Continuous passive motion of the toes improves blood circulation and may help ankle injuries heal faster. Soft devices are more appropriate than rigid devices to accommodate a variety of foot shapes. Most conventional pneumatic soft robots are actuated cyclically by solenoid valves, which require large amounts of power for valves and controllers. In this paper, we introduce a pneumatic oscillator comprised only of passive elements.The device is implemented with a relaxation oscillator based on RC filters from pneumatic components and connected to an inflatable soft actuator. We measured the input and output pressure to verify the RC filter and the oscillation characteristics. Then, we attached the toes CPM device to a participant and measured the toes bending angle and flexing torque. The low-pass and oscillation characteristic of the pneumatic RC circuit was verified. The toes CPM device could bend the toe angle between 15° and 30° with a torque of 1.5 Nm in a 15 s period. Compared to existing solutions, the proposed method allows for toe CPM using only passive pneumatic components which consumes less power and does not require active participation from the user.

Abstract Gain in knowledge in experimental fields of research is mostly achieved using commercial hardware platforms. The linked costs however can limit a broad access by scientists and in the specific case of mechanical ventilation the pandemic demonstrated that further and collective research is essential and necessary. This contribution presents the modular design and implementation of a research platform which is based on STM32 Nucleo boards and Simulink®. The hardware required such as the pneumatic circuit are covered as well as the software architecture in which clinician related settings are processed for control references. The core functionality of mandatory volume controlled (VCV) and pressure controlled ventilation (PCV) while ensuring a positive end-expiratory pressure for the patient ( PEEP ) $(\text{PEEP})$ is evaluated and the foundational software models are published in a repository.