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Multi-axis actuation robotics systems comprising many joints with floating-base require more stability and safety than fixed robots and thus require more considerations. In this paper, the implementation of a real-time EtherCAT control system for the TOCABI humanoid robot with 33 degrees of freedom (DOF) is described. The focus is on the developmen...
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... experiment was conducted to evaluate the impact of RTnet on the real-time stability of the TOCABI's whole-body control algorithm [23], which was performed simultaneously with kinematics and dynamics calculations. The results of the 4KHz experiment, including the average, minimum, maximum, and standard deviation of latency, receive and send times, are shown in Table 2 and Table 3, and represented in histograms in Fig. 8. The results of the 8KHz experiment are shown in Table 4 and Table 5, and represented in histograms in Fig. 9. ...Similar publications
Autonomous multicopters often feature federated architectures, which incur relatively high communication costs between separate hardware components. These costs limit the ability to react quickly to new mission objectives. Additionally, federated architectures are not easily upgraded without introducing new hardware that impacts size, weight, power...
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... It can achieve a bandwidth of up to 1 Gbps or even 10 Gbps. This communication protocol was used in the Atlas [15], TALOS [16], Hydra [17], TOCABI [18], and WalkMan [19] robots. ...
... (iii) the software latency does not exceed 58 µs, and the deterministic behavior is achieved. Our results show an improvement of 20% for the update rate over those reported by [18], where they achieved a 4 kHz update rate, which is the highest rate according to our knowledge. Also, the results show a reduction by approximately 40% in the control task latency compared to those achieved in [32]. ...
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.
... The master-slave structure and distributed clock synchronization technology of EtherCAT enable highly efficient data transmission in the network, facilitating low communication latency to meet the real-time requirements of force-controlled polishing. This integration reduces system costs and enhances overall performance [34][35][36]. The first component of the hardware architecture, referred to as the master, comprises an industrial PC serving as the central control device in EtherCAT master-slave communication. ...
... requirements of force-controlled polishing. This integration reduces system costs and enhances overall performance [34][35][36]. The first component of the hardware architecture, referred to as the master, comprises an industrial PC serving as the central control device in EtherCAT master-slave communication. ...
During the polishing process of complex curved PMMA parts, the polishing force is an important factor affecting the surface quality and optical performance. In this paper, a force-controlled polishing device integrated into a machining center to maintain the polishing force is investigated. In order to achieve the real-time active control of the polishing force, the linear voice coil motor and force sensors are used for motion and measurement. A compact structure was designed to couple the linear motion of the voice coil motor with the rotation for polishing. The force-controlled polishing system with a high real-time hardware architecture was developed to perform complex curved polishing path movement with precise force control. Next, the polishing force between the device and the workpiece was analyzed to obtain the mathematical model of the device. Considering the impact during the approaching phase of polishing, a fuzzy PI controller was proposed to reduce the overshoot and response time. To implement the control method, the controller model was established on Simulink and the control system was developed based on TwinCAT 3 software with real-time computing capability. Finally, a polishing experiment involving a complex curved PMMA part was conducted by a force-controlled polishing device integrated into a five-axis machining center. The results show that the device can effectively maintain the polishing force to improve surface quality and optical performance.
... The data transmission utilises Ethernet. The EtherCAT bus enables parallel transmission, effectively improving the reliability and speed of motion control and data communication (Ahn et al., 2023). The motion control mode of the robotic arm based on EtherCAT is the cyclic synchronous position mode. ...
Feeding remains a critical component in rabbit farming. In rabbit production, precise feeding is imperative, given its significant role in augmenting feed efficiency, curtailing farming expenses, reducing disease prevalence and mortality rates, and lessening environmental pollution. This study presents the design and development of a rabbit feeding robot that synergises mobile robotics and mechanical arm technology, aiming for exact feed dispensation within rabbit hutches through a mechanism that precisely quantifies feed volume. The robot developed for this purpose notably minimises feed fragmentation and mitigates stress responses in rabbits, thus facilitating unsupervised, precise feeding tailored to varied dietary needs. Experimental outcomes, garnered within a rabbit hutch, reveal that the mobile robot operated at velocities between 0.05 and 0.20 m s − 1. Its navigation and positioning accuracy showed a speed deviation of 1.2 %, a lateral deviation of 5.3 mm, a longitudinal deviation of 7.6 mm, and an angular deviation of 1.1 •. The rabbit feeding robot demonstrated a feed quantitative error of 4.3%. At a designated feeding point, the time cycles for dispensing feed across three boxes were recorded as 40.6 s, 50.1 s, and 24.3 s, achieving success rates of 96.3 %, 98.8 %, and 100.0 %, respectively. These results substantiate the practical applicability of the rabbit feeding robot in farming production, thus fostering the progression of intelligent agricultural practices.
