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Featured Application: The procedure is applied to assemble mechanisms manufactured with carbon composite materials which have hydraulic actuation. Humanoid robots have rapidly become the focus of research in recent years, with the most impressive humanoids being hydraulically actuated. This is due to the capacity of hydraulic actuation to provide simultaneous high forces with dynamic motion. The scarcity of hydraulic robots is mainly due to the difficulty in managing hydraulic pipes. These decrease the robot's social acceptance and safety and are the main source of leaks. Recently, there has been a new trend in hydraulically actuated robots that involves creating internal oil passages within the robotic parts to eliminate the need for external flexible tubes. Developing these parts using carbon composite materials provides an additional advantage of ensuring lightweight yet robust robotic parts. However, assembling hydraulically integrated parts is challenging due to the leakproof requirement and the high pressures involved. This article proposes a new, reliable, and effective method that ensures a strong, leakproof assembly. A mathematical model with 11 parameters describing the assembly zone and accounting for geometric parameters, material characteristic parameters, and porosity has been developed. A numerical model was conducted to evaluate the effect of these parameters on the state of the assembly. Experimental validation was conducted to evaluate the assembly force. A satisfactory convergence between the mathematical model and the experimental results was observed with a maximum deviation of 20 % . [ABSTRACT FROM AUTHOR]

Electro-hydraulic actuators have witnessed significant development over recent years due to their remarkable abilities to perform complex and dynamic movements. Integrating such an actuator in humanoids is highly beneficial, leading to a humanoid capable of performing complex tasks requiring high force. This highlights the importance of safety, especially since high power output and safe interaction seem to be contradictory; the greater the robot's ability to generate high dynamic movements, the more difficult it is to achieve safety, as this requires managing a large amount of motor energy before, during, and after the collision. No matter what technology or algorithm is used to achieve safety, none can be implemented without a stable control system. Hence, one of the main parameters remains the quality and reliability of the robot's control architecture through handling a huge amount of data without system failure. This paper addresses the development of a stable control architecture that ensures, in later stages, that the safety algorithm is implemented correctly. The optimum control architecture to utilize and ensure the maximum benefit of electro-hydraulic actuators in humanoid robots is one of the important subjects in this field. For a stable and safe functioning of the humanoid, the development of the control architecture and the communication between the different components should adhere to some requirements such as stability, robustness, speed, and reduced complexity, ensuring the easy addition of numerous components. This paper presents the developed control architecture for an underdeveloped electro-hydraulic actuated humanoid. The proposed solution has the advantage of being a distributed, real-time, open-source, modular, and adaptable control architecture, enabling simple integration of numerous sensors and actuators to emulate human actions and safely interact with them. The contribution of this paper is an enhancement of the updated rate compared to other humanoids by 20% and by 40 % in the latency of the master. The results demonstrate the potential of using EtherCAT fieldbus and open-source software to develop a stable robot control architecture capable of integrating safety and security algorithms in later stages. [ABSTRACT FROM AUTHOR]

Sandwich panels are used in many industries for their lightweight compared to high strength. Most of the sandwich panels application are bending and compression, which relies on the core type of the panel. Widely used in additive manufacturing is pyramid cell cores. In this article, two new cores, the reinforced pyramid cell model and the C-half circle cell model, are proposed to replace the pyramidal core and to verify their advantages and disadvantages with respect to it compression and in bending. The comparison was done in the ABAQUS simulation. A semi-analytical method was used as well as experimental tests were carried out to verify the numerical simulation on ABAQUS. The results have been validated, the difference remains below 10%. According to the simulations, the deformation of the skin of the half circle cell panel decreases by 15% in compression while the deflection of the reinforced pyramid cell panel decreases by 26% in bending compared to the pyramid cell panel. However, the most effective results in absorbing compression are half circle cell which is allowed to make impact insulation. [ABSTRACT FROM AUTHOR]

This paper presents a new hydraulic robotic leg for the humanoid hydraulic robot HYDROïD. The main parts of this leg are divided into two main parts; the knee subsystem and the ankle subsystem. The presented leg mechanism consists of 4 DOFs, all of which are operated using highly dynamic servo valves. The design of the leg is thoroughly presented and all of its parts are demonstrated. Moreover, the inverse kinematics for both sub-mechanisms are presented to be able to control the angular position of the leg joints. Also, a virtual dynamic model is introduced in which a position controller is applied to the model to regulate the actuating pistons, check the new structure, and analyze the position of the joints and their torques. To test the new leg experimentally, the new leg is assembled with the rest of the robot, and rapid prototyping software is used with a position controller. Experimental position tracking responses are introduced showing the validity of the new design and the implemented controller. [ABSTRACT FROM AUTHOR]