Motion Analysis for Jumping Discus Throwing Correction

The purpose of this study was to explore the kinematical characteristics of jumping discus throwing. Eight male right-handed discus throwers who used to practice the jumping throwing technique were recruited as participants. Two high-speed digital cameras with 120 Hz sampling rate were synchronized to capture the movement. The captured images were processed using a motion analysis suite, and the markers attached to joints on images were digitized manually. Based on the results, throwers should keep smaller the shoulder–hip twisting and the right anterior superior iliac spine (abbreviated: ASIS) in front of the right acromion (for right-handed throwers) from the instant the right foot lands to the instant the left foot lands, before the instant of the right foot lands; keep the discus at a depressed position; and reduce the time before discus release, particularly the time of the non-support phase and the second single-support phase. Additionally, release velocity must be improved because throwing distance is directly proportional to squared release velocity. In conclusion, the current study demonstrated comprehensive kinematical analyses, which can be used to instruct the jumping discus throwing technique with duration and angle characteristics of throwing movement for athletes by coaches with videos.

Planar Five-link Biped Robot Movement over a Stepped Surface

Modeling the anthropomorphic robot movement is of great interest to researchers all over the world. At the same time, the movement control of a walking mechanism is always a high dimension challenge. The difficulty with the anthropomorphic robot control is also caused by the fact that such a mechanism has always a hybrid dynamics and represents a sequential change of two phases – the single support phase and the double support phase (phase of changing robot’s leg). At the single support phase and at another phase the behavior of the biped robot is described by a system of ordinary differential equations and by a system of linear algebraic equations, respectively.The task of biped robot movement control has been studied in detail for the case when the robot moves over the horizontal surface. Obstacles make the task significantly complicated. The paper considers the movement control of the biped robot over the surface that is a periodic alternation of horizontal sections and obstacles. The obstacles represent steps of the same height known. It is assumed that the lengths of horizontal sections and steps are known as well. The objective is to create a control that provides robot’s periodic movement over the specified surface according to inherent characteristics of a walking human.For the single support phase, the outputs are proposed, the equality of which to zero corresponds to the robot’s movement with a given set of characteristics. The paper presents the feedback controls that stabilize the proposed outputs for a finite amount of time. By choosing the feedback parameters, it is possible to adjust the stabilization time so that the outputs become equal to zero when reached the end of each step.It is shown that for the chosen control law, the problem of constructing the control of robot’s periodic movement is reduced to the solution of a nonlinear equation. In the paper, we discuss the approaches to solving this equation and present the results of numerical simulation.The results obtained can be used to solve the problem of providing control of the biped robot movement over the surfaces with obstacles of a more complicated shape.Modeling the anthropomorphic robot movement is of great interest to researchers all over the world. At the same time, the movement control of a walking mechanism is always a high dimension challenge. The difficulty with the anthropomorphic robot control is also caused by the fact that such a mechanism has always a hybrid dynamics and represents a sequential change of two phases – the single support phase and the double support phase (phase of changing robot’s leg). At the single support phase and at another phase the behavior of the biped robot is described by a system of ordinary differential equations and by a system of linear algebraic equations, respectively.The task of biped robot movement control has been studied in detail for the case when the robot moves over the horizontal surface. Obstacles make the task significantly complicated. The paper considers the movement control of the biped robot over the surface that is a periodic alternation of horizontal sections and obstacles. The obstacles represent steps of the same height known. It is assumed that the lengths of horizontal sections and steps are known as well. The objective is to create a control that provides robot’s periodic movement over the specified surface according to inherent characteristics of a walking human.For the single support phase, the outputs are proposed, the equality of which to zero corresponds to the robot’s movement with a given set of characteristics. The paper presents the feedback controls that stabilize the proposed outputs for a finite amount of time. By choosing the feedback parameters, it is possible to adjust the stabilization time so that the outputs become equal to zero when reached the end of each step.It is shown that for the chosen control law, the problem of constructing the control of robot’s periodic movement is reduced to the solution of a nonlinear equation. In the paper, we discuss the approaches to solving this equation and present the results of numerical simulation.The results obtained can be used to solve the problem of providing control of the biped robot movement over the surfaces with obstacles of a more complicated shape.

A New Multi Echelon Repair Network Model with Multiple Upstream Locations for Level of Repair Analysis Problem

Level of repair analysis (LORA) determines (1) the best decision during a malfunction of each product component; (2) the location in the repair network to perform the decision and (3) the quantity of required resources in each facility. Capital goods have long life cycles and their total life cycle costs are extremely high. LORA, which can be done repeatedly during the life cycle of the product, both at design and product support phase, plays an important role in minimising the total life cycle costs of capital goods. It is mostly applied to systems that operate in different geographical areas and deployed in different regions, which include different subsystems with special technology and expertise, and have a complex product structure. In this study, we propose a new mathematical model to the LORA problem, which is more comprehensive and flexible than the other pure LORA models in the literature. The proposed model uses the multiple upstream approach that allows the transfer of the components from a location in the lower echelon to the predefined locations in the upper echelon and determines the material movement paths between each facility, defining the facilities’ locations in the repair network. The performance of the proposed model is tested on benchmark instances and the results are compared with the single upstream model. Computational experiments show that the proposed model is more effective than the single upstream model and reduces the total life cycle costs by 4.85% on average, which is an enormous cost saving when total life cycle costs of capital goods are considered.

A New Foot Trajectory Planning Method for Legged Robots and Its Application in Hexapod Robots

Compared with wheeled and tracked robots, legged robots have better movement ability and are more suitable for the exploration of unknown environments. In order to further improve the adaptability of legged robots to complex terrains such as slopes, obstacle environments, and so on, this paper makes a new design of the legged robot’s foot sensing structure that can successfully provide accurate feedback of the landing information. Based on this information, a new foot trajectory planning method named three-element trajectory determination method is proposed. For each leg in one movement period, the three elements are the start point in the support phase, the end point in the support phase, and the joint angle changes in the transfer phase where the first two elements are used to control the height, distance, and direction of the movement, and the third element is used make decisions during the lifting process of the leg. For the support phase, the trajectory is described in Cartesian space, and a spline of linear function with parabolic blends is used. For the transfer phase, the trajectory is described in joint-space, and the joint angle function is designed as the superposition of the joint angle reverse-chronological function and the interpolation function which is obtained based on joint angle changes. As an important legged robot, a hexapod robot that we designed by ourselves with triangle gait is chosen to test the proposed foot trajectory planning method. Experiments show that, while the foot’s landing information can be read and based on the three-element trajectory planning method, the hexapod robot can achieve stable movement even in very complex scenes. Although the experiments are performed on a hexapod robot, our method is applicable to all forms of legged robots.

Artificial Intelligence in Repairing Meniscus Injury in Football Sports with Perovskite Nanobiomaterials

Knee meniscus injuries are more likely to occur in young adults in clinical practice, and their lower age of onset and greater impact on joint function after injury also put forward higher requirements for the treatment and rehabilitation of meniscus injuries. With the rapid development of artificial intelligence technology and arthroscopic minimally invasive technology, arthroscopic meniscus plasty and perovskite nanobiomaterial repair have gradually replaced the previous open meniscus surgery of the knee joint and has become the main method of meniscus injury treatment, and the perovskite nanobiomaterial repair technique that incorporates artificial intelligence technology is also gradually being applied. Therefore, this article studies the role of perovskite nanobiomaterials in the repair of meniscus injuries in football sports and analyzes the biological characteristics of the inner and outer meniscus to provide help to improve the healing rate of meniscus injuries. The study selected six male meniscus-injured patients (meniscus injuries caused by football sports) and obtained six injured menisci. The same cross section of the same part of the meniscus was analyzed inside and outside the meniscus. At the same time, a meniscal injury step was performed on the patient. The biological characteristics of perovskite nano-biomaterials in the repair of meniscus injuries in football sports were compared and analyzed, and the patient's gait before and after surgery was also compared. Experiments have shown that the percentage of the postoperative support phase of the affected limb is significantly higher than that before surgery ( P < 0.05 ), the percentage of the postoperative support phase and flatfoot phase decreased compared with that before surgery, and the gait cycle parameters of both lower extremities improved after surgery, obviously ( P < 0.05 ). It explains that the arthroscopic repair of perovskite nanobiomaterials combined with the artificial intelligence technology to repair the meniscus anterior angle injury is simple and does not require special equipment, has fewer complications, is safe and reliable, and has a high clinical healing rate and a high patient satisfaction rate after surgery. The curative effect is significant; artificial intelligence technology and the application of perovskite nanobiomaterials provide more possibilities for meniscus repair.

Low composite functional movement screen score associated with decline of gait stability in young adults

Background The functional movement screen (FMS)TM is a screening tool used to evaluate fundamental motor function. A score of 14 for the composite total FMS score (TFMS) is generally used as the cut-off point (≤14/21). In addition, gait analysis is used to evaluate fundamental motor function in humans. Thus, evaluating the fundamental motor function using the FMSTM test and gait analysis at various speeds can provide further understanding of any decline in gait stability. In this study, we aimed to investigate the association between gait ability and fundamental movement patterns in young adults according to the cut-off point. Methods A total of 439 participants (male: 203, female: 236) successfully completed the FMS test and a 1 min treadmill test; the participants were classified into two groups: low TFMS (≤14) and high TFMS (>14). Results The low TFMS group exhibited slower and shortened walking patterns and worsen gait variability than the high TFMS group. The coefficient of variance (CV) for the double support phase at a faster speed (male) and the stride length at a slower speed (female) were classifiers between the two groups. In addition, the low TFMS group demonstrated insufficient gait adaptation at the preferred and faster speeds based on the CV of the double support phase and gait asymmetry. Lower TFMS is associated with a decline in gait ability. Therefore, participants with a lower TFMS and poor gait ability may require intervention programs to prevent risk of future injury and to enhance motor function.