جستجوی مقالات مرتبط با کلیدواژه "walking" در نشریات گروه "فنی و مهندسی"

Despite the extensive progress in the field of biomechanics of human gait, a suitable gait model with the ability to simulate the control system of the human brain has not yet been presented, especially in 3D mode. The importance of the issue increases when the simulation of human walking is one of the main requirements of designers of biomechanical equipment such as artificial organs, wearable robots and humanoid robots. Regarding the constraints and complexities of previous studies, in this research, a forward dynamic 3D model of gait based on sliding mode controller (SMC) is presented, which simulates the walking behavior of healthy individual on the ground in different movement phases. One of the strengths of this research is the comprehensive and analytical review of 3D rotation consequences of the joints coordinate systems, which is done with 11 DOF inverse dynamic model. Based on the obtained results, the SMC controller is well able to produce stable 3D human gait. Also, in 3D gait analysis, the Cardan rotation sequence is not suitable and YXZ order should be used. This outcome is a very useful result for 3D motion generation for human like walking pattern. The results of this study can be used in the design of humanoid robots, active and passive prostheses. Also, the presented model can simulate the walking of an amputee with a prosthesis and the role of the controller in the path, which is very important and beneficial in terms of rehabilitation.

In recent decades, due to the significant increase in the elderly in the age pyramid of most of the country, wearable orthoses have received more attention with regard to rehabilitation. Sudden falls are one of the most important factors leading to death in the elderly. In this article, the impact of an orthosis on human balance while standing and walking has been investigated. The effect of this simple orthosis in reducing body metabolism while walking has been studied. In this article, the experimental effect of this orthosis on people's balance has been investigated. For this purpose, the desired orthosis was designed and manufactured. Then a data bank was created by the results of the experiments. To compile this data, the results of the experiments conducted by 10 volunteer students were used. In these tests, ear fluid and vision indicators were analyzed on the performance of people when using this orthosis. The findings of the studies are related to the study between people. According to the results of the tests, the use of the above orthosis improves the performance of people in the dynamic body, while the results of this research on static performance do not show any effect.

Walking between school and home is a good opportunity for students to reach the recommended level of physical activity during the day. The paper aims to investigate the effect of individual and family factors on the walking of primary school students to school. The study students (n: 1503) were randomly selected from 18 primary schools in Shiraz. The questionnaire included the student's travel type, their individual characteristics (age and gender), family characteristics (parental occupation and education, average income and so on) were completed and analyzed using the binary logistic regression model. Findings showed girls have less tendency to walk. In addition, increasing the father's level of education reduces walking among students. Moreover, an increase in the number of children in the family, having active daily trips by mothers and Improving parents' attitudes toward the quality of passages will increase students walking to school. Meanwhile, car ownership, the number of family members with driving licenses, average income, and parental attitudes toward traffic accidents and parental perception toward the walking time to school were indirectly related to a student walking. The present study highlights the importance of individual and family factors on students' walking rates for urban planners and policymakers. One of the important results of this study is that by changing the pattern of mother daily trips from personal vehicles to active trips, students will be more likely to walk to school.

The study of effective factors in the selection of intra-city trips is one of the important issues in urban planning. So far, adult travel behavior for various purposes has been extensively investigated by transport planners and urban scholars, and many conceptual models have been developed for this purpose, but less attention has been paid to students' study trips. On the other hand, studies have recently been conducted on the selection of travel equipment for students in metropolitan areas such as Tehran and Mashhad, but less attention has been paid to middle cities with less populations and more traditional tissue. In this research, factors affecting the choice of the tool for student trips to the middle city of Ardabil have been investigated. Based on the general census of population and housing in 1395, the population of the city of Ardabil was 529,374 people in the form of 15,827 households, of which 14.8 are from 7 to 13 years (grades one to six), so that 64.6% of boys and 17.7% of girls are. In this regard, student's travel data was collected by questioning. In this questionnaire, 600 questionnaires distributed among 496 return questionnaires, 411 questionnaires were used. After the initial analysis of the data, using a multi-logit model with randomized decomposition, modeling was used to select the method of study trips for students in Ardabil city. The results of the studies show that the socio-economic characteristics of the parents of the household have a significant impact on the method of selecting the travel means of the students.

Analysis of movement data is a new trend of research in GIScience. Recent and emerging positioning technologies and wearable sensors such as smart watches have led to increases in the availability of various kinds of data for moving objects. Thus, new exploratory tools and knowledge discovery techniques are required to extract meaningful information, discover interesting patterns, and explore the dynamic behaviour of moving objects in order to transform raw trajectory data into useful information to be used in reality interpretation and decision making. Especially, analysis of movement observations, which contain information about the movement of each individual entity and the underlying mechanisms, are of great interest. These observations are key to the study and understanding of movement behaviour. It is essential for movement behaviour studies to take into consideration the so-called movement parameters (MPs), e.g. speed, acceleration, or direction, which are key to characterize the movement of objects. For example, in some sports, it is important to be aware of the heart rate or speed patterns of athletes through running or walking at different times of the day in order to detect the athletes’ performance. In such cases, analyzing a persons’ movement observations in terms of space (x, y, z) and time (t), through considering movement attributes of each person and contextual information (e.g. the environmental information such as temperature) will allow a better understanding of behavioural movement patterns and effect of different parameters on patterns as well. This article proposes analysing walking observations to extract behavioural pattern of attributes (such as speed and heart rate) of a person to examine the influence of different conditions on behavioural movement patterns. For this, a segmentation approach is proposed to project the “movement parameter profiles” into a pattern for analyzing changes in different movement attributes of each individual during walking in order to identify the effect of each personal context (e.g. gender of the person) and environmental context (e.g. day time, tiredness, weather condition, etc.) on the movement patterns. A measure to assign distance value is then used to examine the effect of contexts on the movement. As expected, the results show that time series of each attribute for each person have a unique pattern describing the persons’ movement behaviour, which changes in different contexts. For detecting the effect of different personal and environmental conditons on the behavioral movement patterns of people during walking, the comparing procedure was implemented on movement parameter patterns with the same conditions and different conditions respectively and a running index was introduced to model the similarity and persons performance during walking. This model was used to predict the similarity between the movement parameter patterns with different conditions. Finally, by comparing the predicted value and the similarity which calculated by proposed approach, we could reach the effect of different situation on behavioral movement pattern of people during walking.

Biped robots with point feet demonstrate faster gaits and more natural dynamics while their gait planning is very difficult due to their underactuation. This research focuses on modelling, optimization and gait generation of two different real biped models including a telescopic springy biped model and compass gait biped with kneed swing leg. All of these models have point feet and their torso angle is constrained and they move in sagittal plane. The main difference of these models with their corresponding theoretical models is that to give realization to the gaits of these models the knee of their swing leg bends, clears the ground and straightens before touch-down. This increases degrees of freedom and divides single support phase to two sub-phases. Different phases of walking gait of each model including single support phase, touch-down event and double support phase are modeled using Lagrange equation and validity of equations are demonstrated. Then the dynamic equations of the phases are combined together to make dynamic model of a full walking gait. Afterwards, optimization parameters, objective functions and constraints are presented and successive stages of optimization are performed to find optimal gaits. The optimization diagrams are discussed and the needed motor torques for the optimal gait of each model are illustrated.

Simultaneously with escalation of industrialization in the cities and the dominant presence of vehicle on the urban texture environmental quality especially of urban areas¡ the historic and central part of cities decline and lead to problems of access and transportation¡ severe interaction of car and pedestrians and violation of Non-motorised users rights in the space. Use of sustainable transport strategies such as cycling and walking is one of the practical solutions to heal the problems of this texture that play a great role in reducing travel costs¡ increased social efficiency¡ safety and security of citizens¡ reduce the damaging effects of environmental¡ health and etc. This paper summarizes the status of access and mobility in inner cities sustainable modes of walking and cycling more and more to accommodate with the physical characteristics of this part of the city has been suggested. In order to effectively implement these strategies¡ some of the services of intelligent transport systems (ITS) are presented to promote¡ support and maintenance the safety of users of these two modes of movement.

Control of biped robots based on the concept of asymptotical stable periodic motions have become of interest of researchers nowadays. Potential energy shaping, one of the most significant approaches in this regard, has been presented and evaluated well on planar 2D models, so far. In this paper, this concept is developed and investigated for general three-dimensional case, in the presence of non-holonomic constraints. At First, the considered biped model is a 3D compass gait model with finite hip width and arc shaped feet whose stable passive walking has been shown in previous researches. In this approach, the passive periodic gaits which may be adopted for a particular ground slope can be reproduced on any arbitrary ground slope such as flat surface. In fact, thanks to the invariance property of kinetic energy as well as equivariance property of collision map with respect to slope changing action, this important goal is reached only by compensating the potential energy similar to that of passive walker. In another word, inducing a controlled symmetry to the system Lagrangian, we impose a virtual gravity in a new direction resembling the gravity direction of passive walker with respect to the ground. At the end, regarding practical challenges about the implementation of arc feet model, a compass gait model with flat feet and springs at the ankle joint has been proposed instead and the aforementioned control approach is applied again. Simulation results show the effectiveness of the presented approach for both models well.

For urban transportation development there are a lot of annual costs, such as fuel importation, roads development, car repairing. Also environmental transportation impacts like energy consumption, noise and air pollution, increase the mentioned costs. Along rapid urban development it has become a considerable concern in the urban environmental management. Therefore, urban transportation is an important area in the field of environment. Hence it is required to pay more attention to environmental management of urban transportation. One of the useful management methods is development of Non-motorized Urban Transportation (bicycling and walking). The overall objective of this study is to develop a GIS model to plan suitable locations for non-motorized urban transportation. Arak, a developing city in Iran has been chosen as a case study. Methodology of this study helps to select suitable sites for development of non-motorized urban transportation. GIS as a powerful tool is applied for layers overlaying and interpretation of several scenarios. The results as the accessibility map and analysis for 3 transportation options (motorized transportation, bicycling and walking), shows high suitability of the study area for development of non-motorized urban transportation. Regarding fuel consumption issue, there are a lot of non-suitable location of main destinations in urban transportation network. This research has successfully managed development of a scientific approach for current and future development. It can be employed in transportation planning and suitability assessment at the local and national structure plan levels.

One major limitation of walker-supported walking using functional electrical stimulation (FES) in paraplegic subjects is the high energy expenditure and the high upper body effort. Paraplegics should exert high amount of hand force to stabilize the body posture and to compensate lack of the sufficient torques at the lower extremity joints. In this paper, we introduce a 2-D musculoskeletal model of walker-assisted FES-supported walking of paraplegics. Using the developed model and an optimal controller, the stimulation patterns are determined such that the tracking errors of lower joint reference trajectories are minimized and the muscle activations and the handle reaction force (HRF) are reduced. Outputs of the optimal controller are stimulation patterns of the lower body muscles and torque acting on the upper body joints. The results show that the HRF and ground reaction force (GRF) generated by simulation are in agreement with the measured HRF and GRF. Moreover, the results indicate that the simulation-generated stimulation patterns of lower body muscles are in consist with the stimulation patterns reported in the literatures.