Very High Movement Speed in a Hitting Action Affects Interjoint Coordination But Not Spatial Accuracy.

This paper addresses the development and applications of the control system based on the real-time operating system (RTOS) RTX which constructs an open architecture control system with real-time performance, flexibility and low cost. In this paper, the RTX-based control system is considered from RTOS evaluation, system-level design, to experiments and applications. A novel software structure consisting of Windows, Labview or Matlab, and RTX is presented, which makes the trade-off between real-time tasks running and data processing or displaying. Finally, the control system is successfully applied in two direct-drive high speed and high precision motion platforms.

In this paper, we studied the Position&Force servo control of the voice coil motor commonly used in semiconductor packaging equipment and analyzed its Position&Force servo control switching strategy. System identification is the basis for high-speed, high-precision motion control. We use the frequency domain identification method to identify the voice coil motor system. The frequency domain identification method uses sine sweep frequency and PRBS method to compare and verify. Feedback and feedforward servo control structures are used to ensure quick response and precise control of voice coil motors while ensuring system stability. In the feedforward control, we use an iterative learning control method. In semiconductor packaging equipment, the movement of the voice coil motor has always been a similar process cycle. Iterative learning control (ILC) has prominent control effects in situations where control objectives and external disturbances are periodic or repetitive. The iterative learning control algorithm is applied to the feedforward plus feedback servo control structure of the voice coil motor. From the actual effect point of view, the trajectory tracking ability of the voice coil motor during high-speed motion is significantly increased. The voice coil motor servo control algorithm described above is written on the DSP and verified on the motion control card. The experimental results show that the above servo control algorithm realizes the high speed and high precision motion control of the voice coil motor.

Rapid technological advance in wireless mobile communication offered Internet accessibility at anytime and anywhere including high speed wireless environment such as in high speed trains, fast moving cars etc. However, wireless Quality of Service (QoS) provisioning in such high speed movement is more difficult and challenging to be tackled than in a fixed-wired environment. This paper discussed transport layer protocol, SCTP to support seamless handover that can guarantees and maintain high QoS in high speed vehicle. The comparison of the selected protocol have been identified and analysed in two handover techniques SIGMA and SCTPmx to optimize its performance in high speed vehicular environment.

Analysis of arm elevation muscle activity through different movement planes and speeds during in-water and dry-land exercise

Visual servoing of tools and object detection are major tasks of serial micro-assembly, as the visual feedback is often the only way to track positions. High speed cameras can be used for high speed automated micromanipulation. This paper analyzes different object tracking approaches for their feasibility of high speed tracking. First, state of the art software algorithms are analyzed. Second, a hardware approach is analyzed. All algorithms are compared in terms of high-speed feasibility, movement speed and limitations. The comparison shows that hardware-based approaches are needed for update frequencies beyond 100 Hz.

To compare the biomechanical properties of personalized Y-shaped plates with horizontal plates, vertical plates, and traditional Y-shaped plates in the treatment of distal humeral intra-articular fractures through finite element analysis, and to evaluate their potential for clinical application. The study selected a 38-year-old male volunteer and obtained a three-dimensional model of the humerus by scanning his upper limbs using a 64-slice spiral CT. Four types of fracture-internal fixation models were constructed using Mimics 19.0, Geomagic Wrap 2017, Creo 6.0, and other software: horizontal plates, vertical plates, traditional Y-shaped plate, and personalized Y-shaped plate. The models were then meshed using Hypermesh 14.0 software, and material properties and boundary conditions were defined in Abaqus 6.14 software. AnyBody 7.3 software was used to simulate elbow flexion and extension movements, calculate muscle strength, joint forces, and load torques, and compare the peak stress and maximum displacement of the four fixation methods at different motion angles (10°, 30°, 50°, 70°, 90°, 110°, 130°, 150°) during elbow flexion and extension. Under dynamic loading during elbow flexion and extension, the personalized Y-shaped plate exhibits significant biomechanical advantages. During elbow flexion, the peak internal fixation stress of the personalized Y-shaped plate was (28.8±0.9) MPa, which was significantly lower than that of the horizontal plates, vertical plates, and traditional Y-shaped plate ( P<0.05). During elbow extension, the peak internal fixation stress of the personalized Y-shaped plate was (18.1±1.6) MPa, which was lower than those of the other three models, with significant differences when compared with horizontal plates and vertical plates ( P<0.05). Regarding the peak humeral stress, the personalized Y-shaped plate model showed mean values of (10.9±0.8) and (13.1±1.4) MPa during elbow flexion and extension, respectively, which were significantly lower than those of the other three models ( P<0.05). Displacement analysis showed that the maximum displacement of the humerus with the personalized Y-shaped plate during elbow flexion was (2.03±0.08) mm, slightly higher than that of the horizontal plates, but significantly lower than that of the vertical plates, showing significant differences ( P<0.05). During elbow extension, the maximum displacement of the humerus with the personalized Y-shaped plate was (1.93±0.13) mm, which was lower than that of the other three models, with significant differences when compared with vertical plates and traditional Y-shaped plates ( P<0.05). Stress contour analysis showed that the stress of the personalized Y-shaped plate was primarily concentrated at the bifurcation of the Y-shaped structure. Displacement contour analysis showed that the personalized Y-shaped plate effectively controlled the displacement of the distal humerus during both flexion and extension, demonstrating excellent stability. The personalized Y-shaped plate demonstrates excellent biomechanical performance in the treatment of distal humeral intra-articular fractures, with lower stress and displacement, providing more stable fixation effects.

In certain extreme environments where infrastructure such as base stations is absent, connections between nodes can be intermittent. Traditional networks struggle to function in these conditions. Delay Tolerant Network (DTN) are a network architecture designed for such scenarios. Utilizing Unmanned Aerial Vehicle (UAV) as nodes within DTN can enhance the network’s transmission capabilities and compensate for the deficiencies of ground nodes. However, previous routing methods have shortcomings. Given the high speed and greater freedom of movement of UAVs compared to ground nodes, the network topology is subject to constant and significant change. Traditional routing methods, which typically rely on predetermined rules for selecting forwarding nodes, struggle to adapt to such variations. This paper introduces Graph Neural Network (GNN) into routing decisions for DTN to learn network structural information and assist with routing decisions. In this paper, we first model the routing problem within DTN, accounting for the dynamic changes in network topology and limited resources. Subsequently, we propose a GNN-based dynamic routing method. This method utilizes a graph neural network model that takes as input the feature s of nodes at the current moment and the network’s connectivity information to generate optimal forwarding nodes for each data packet. The proposed method has been implemented in the Opportunistic Networking Environment (ONE) simulator. Experimental results indicate that our method achieves higher delivery ratio, lower latency, and reduced overhead compared to traditional methods.

Stick-slip piezoelectric actuators exhibit the advantages of simple structure, compact size, high resolution, and fast motion speed, enabling millimeter-scale motion range with nanometer-level positioning accuracy. Owing to these unique features, they hold strong potential for high-precision positioning in advanced microsystems, biomedical engineering, optical instrumentation, and other emerging technologies. However, current high-speed stick-slip piezoelectric actuators suffer from the problems of unstable motion, actuator damage, and contact wear due to the high-frequency driving. In this paper, by combining the parallelogram with the triangular mechanism, a two-stage compliant amplification mechanism is integrated into the stick-slip piezoelectric actuator to achieve low-frequency driving and high-speed motion simultaneously. Based on the compliance matrix method, a theoretical model is developed and utilized for structural optimization. Finite element analysis is conducted to verify its accuracy. The performance of the actuator is further investigated by testing the prototype. The experimental results demonstrate that a maximum motion speed of 20.51 mm/s is achieved under driving frequency of only 300 Hz and driving voltage of 100 V. Furthermore, the largest vertical load that the piezoelectric driver can support is 700 g when the locking force is 5 N. Compared with the previous studies, the proposed actuator presents good low-frequency driving and high-speed motion performance.

Self vs. external attribution of motions based on vestibular cues is suggested to underlie our coherent perception of object motion and self-motion. However, it remains unclear whether such attribution also underlies sensorimotor responses. Here, we examined this issue in the context of touch. We asked participants to lightly touch a moving object with their thumb while standing still on an unstable surface. We measured both the accuracy of judging the object motion direction and the postural response. If the attribution underlies both object-motion perception and posture control, sensitivity of posture to object motion should decrease with motion speed since high speed motion is unlikely to reflect self-motion. Furthermore, when motion perception is erroneous, there should be a corresponding increase in postural responses. Our results are consistent with these predictions and suggest that self-external attribution of somatosensory motion underlies both object motion perception and postural responses.

Zero moment point (ZMP) is an important balance criterion for human motion planning. An important term in the ZMP formula is the rate of angular momentum (RAM) of each link. It is not trivial to compute this term compared to other terms in ZMP formula. In this paper, we first propose an efficient recursive Lagrangian method for calculating the rate of angular momentum in ZMP. This new approach gives a direct way to calculate the rate of angular momentum for each link. Secondly, we evaluate the effects of RAM in ZMP on human motion predictions for walking and running. These two motions are characterized as low speed and high speed motions respectively. We conclude that it is critical to include RAM in ZMP to predict accurate high speed motion. It has relatively less effect on low speed motion.

To fabricate a "mechano-active" tubular scaffold of nonwoven mesh-type small-diameter artificial graft made of the synthetic durable elastomer, segmented polyurethane, the fabrication technique of electrospinning on a mandrel under a high rotation speed and transverse movement was used. Emphasis was placed on how the rotation speed of the mandrel and the fusion or welding states of fibers at contact points affect the compliance (ease of intraluminal pressure-dependent circumferential inflation) and Young's modulus determined by uniaxial stretching in the longitudinal and circumferential directions. The results showed that a high rotation speed is attributed to exhibit isotropic mechanical properties in the entire range of applied strain but reduces the compliance, and a high fusion state, which is produced using a mixed solvent with a high content of high-boiling-point solvent, reduces the compliance but is expected to exhibit high durability in a continuously loaded pulsatile stress field in an arterial circulatory system.

This paper introduces study review on nominal characteristic trajectory following (NCTF) controller as a practical controller for point-to-point (PTP) positioning systems. PTP is one type of precision positioning systems that required high accuracy with a high speed, fast response with no or small overshoot and robustness to parameter variations and uncertainties. In PTP applications, parameter varies with the payload and some friction may cause the instability of the performances. In this case, the system performance is expected to be the same or as close as its performance when the system is in normal condition. PTP positioning systems need a good controller to achieve high speed and high precision motion. However, it is not easy to achieve high precision system because of non-linearities and uncertainties exist in the motion control systems. A NCTF controller as a practical controller for PTP had been proposed. The NCTF controller consists of two elements namely a nominal characteristic trajectory (NCT) and a compensator. It had been reported that the NCTF had a good positioning performance and robustness to parameters variations. Application of NCTF control for PTP positioning systems both for one-mass system or multi-mass system are studied and summarized. Fundamental concept of NCTF controller also explained.

Overlapping advance control systems for microelectrode positioning

The enormous progress in the fields of microsystem technology, microelectronics andcomputer science has led to the development of powerful high speed cameras. Recently anumber of such cameras became available as low cost consumer products which can also beused for the teaching of physics. The technology of high speed cameras is discussed,facilitating an understanding of the problems and restrictions in using these cameras.

The magnetic analysis of a new class of eddy-current driven impulse actuators is considered. Driven by capacitor discharge, these actuators generate synchronized force pulses in excess of 100 kN with under 1 kN of recoil force transmitted too the positioner. This technology is being applied to low-payload industrial robots and mechanical impact deicing of aircraft lead edges. These applications are difficult to duplicate experimentally, so there is a demand for computer simulation. The high speed and transient motion of these actuators result in a significant but not constant contribution from velocity-coupled Faraday terms that is not accounted for in conventional finite-element simulation routines. A new computational technique is presented and verified experimentally. >