Academic literature on the topic 'Human Walking - Degrees of Freedom (DoF) Model'

To predict the 3D walking pattern of a human, a detailed upper body model that includes the spine, shoulders, and neck must be made, which is challenging because of the coupling relations of degrees of freedom (DOF) in these body sections. The objective of this study was to develop a discomfort function for including a high DOF upper body model during walking. A multi-objective optimization (MOO) method was formulated by minimizing dynamic effort (DE) and the discomfort function simultaneously. The discomfort function is defined as the sum of the squares of deviation of joint angles from their neutral angle positions. The neutral angle position is defined as a relaxed human posture without actively applied external forces. The DE is the sum of the joint torque squared. To illustrate the capability of including a high DOF upper body, backward walking is used as an example. By minimizing both DE and the discomfort function, a 3D whole-body model with a high DOF upper body for walking was simulated successfully. The proposed MOO is a promising human performance measure to predict human motion using a high DOF upper body with full range of motion. This has been demonstrated by simulating backward walking, lifting, and ingress motions.

ABSTRAKRobot humanoid merupakan robot menyerupai manusia dengan tingkat kompleksitas yang tinggi dan fungsi yang serbaguna. Pada penelitian ini dilakukan analisis model kinematika gerak pada robot bipedal humanoid TFLoW 3.0, serta menganalisis pola gerakan berjalannya. Pola pergerakan yang diimplementasikan pada robot bipedal TFLoW 3.0 merupakan hasil pendekatan dari teori cara berjalan manusia dengan menggunakan enam gerakan dasar manusia saat berjalan. Kemudian menganalisis model gerakan robot menggunakan kinematika terbalik dengan solusi geometri. Tujuan dari model kinematika terbalik adalah untuk mengubah data input berupa posisi kartesian menjadi nilai sudut untuk setiap parameter joint pada masing-masing Degrees of Freedom (DoF). Lalu dilakukan analisis model mekanik robot saat berjalan yang terbagi atas fase tegak dan fase berayun yang bertujuan untuk mengetahui hasil pengujian.Kata kunci: robot humanoid, gaya berjalan, kinematika, TFLoW, DoF. ABSTRACTHumanoid robots are human-like robots with a high level of complexity and versatile functions. In this study, kinematics analyze on TFLoW 3.0 humanoid bipedal robot is carried out, as well as analyzing the pattern of its walking movement. The implemented movement of TFLoW 3.0 bipedal robot is the result of an approach from human walk using six basic human movements when walking. the robot movement model is analyzed by inverse kinematics with geometric solutions. Invers kinematics model is to transform the input data in the form of a Cartesian position into an angle value for each joint parameter in each Degrees of Freedom (DoF). Then an analysis of the robot's mechanical model when walking is carried out which is divided into a stance phase and a swinging phase which aims to determine the test results.Keywords: humanoid robot, gait, kinematics, TFLoW, DoF.

Physiologically and biomechanically, the human body represents a complicated system with an abundance of degrees of freedom (DOF). When developing mathematical representations of the body, a researcher has to decide on how many of those DOF to include in the model. Though accuracy can be enhanced at the cost of complexity by including more DOF, their necessity must be rigorously examined. In this study a planar seven-segment human body walking model with single DOF joints was developed. A reference point was added to the model to track the body’s global position while moving. Due to the kinematic instability of the pelvis, the top of the head was selected as the reference point, which also assimilates the vestibular sensor position. Inverse dynamics methods were used to formulate and solve the equations of motion based on Newton-Euler formulae. The torques and ground reaction forces generated by the planar model during a regular gait cycle were compared with similar results from a more complex three-dimensional OpenSim model with muscles, which resulted in correlation errors in the range of 0.9–0.98. The close comparison between the two torque outputs supports the use of planar models in gait studies.

SUMMARYEnergy expenditure (EE) is an important criterion for design and control of biped walking robots. However, the cause-effect analyses enabled by total EE, which is lumped over a time duration and all system degrees-of-freedom (DOFs), are limited. In this study, robotic gait energetics is evaluated through a DOF-based instrumentation system designed for instantaneous evaluation of bidirectional current and applied voltage at each joint actuator. The instrumentation system includes a dual-module arrangement of buffers and attenuators, and accommodates and synchronizes the voltage and current measurements from multiple actuators. For illustrative purposes, this system is implemented at each DC servomotor in a biped robot, DARwIn-OP, to analyze the electrical EE rates for walking at various speeds. In addition, a DOF-based model of instantaneous human EE rate is employed to enable quantitative characterization of robotic walking EE relative to that of humans. The robot's instantaneous lower-body EE rates are consistent with its periodic walking cycle, and their relative trends between single and double support phases are analogous to those of humans. The robotic cost of transport (COT) curve as a function of normalized speed is also consistent with the human COT in terms of its convexity. Conversely, the contrasting distributions of EE throughout the robot and human DOFs and the robotic COT curve's considerably larger magnitudes, smaller speed ranges, and higher sensitivity to speed illustrate the energetic consequences of stable but inefficient static walking in the biped robot relative to the more efficient dynamic walking of humans. These energetic characteristics enable the identification of the joints and gait cycle phases associated with inefficiency in biped robotic gait, and reflect the noticeable differences in the system parameters (rigid and flat versus segmented feet) and gait control strategies (bent versus straight knees, instants of peak ankle actuator torques, static versus dynamic balance stability). The proposed general instrumentation provides a quantitative approach to benchmarking human gait as well as general guidelines for the development of energy-efficient walking robots.

This paper presents the development of an instrumented exoskeleton with baropodometry, electromyography, and torque sensors. The six degrees of freedom (Dof) exoskeleton has a human intention detection system based on a classifier of electromyographic signals coming from four sensors placed in the muscles of the lower extremity together with baropodometric signals from four resistive load sensors placed at the front and rear parts of both feet. In addition, the exoskeleton is instrumented with four flexible actuators coupled with torque sensors. The main objective of the paper was the development of a lower limb therapy exoskeleton, articulated at hip and knees to allow the performance of three types of motion depending on the detected user’s intention: sitting to standing, standing to sitting, and standing to walking. In addition, the paper presents the development of a dynamical model and the implementation of a feedback control in the exoskeleton.

Legs are the mostimportant elements for accomplishing human physical work includingtransportation or displacement. In this paper, a new mechanism for human legmotion assistance has been proposed for rehabilitation purposes. The structureof human leg and its motions have been used as inspiration for design purposes.For a simple control algorithm, the proposed mechanism for the legs mustgenerate an ovoid path of the foot, by uniform rotating of actuating crank. Themechanism must generate an approximately linear trajectory of foot duringpropulsion. The resulting linkage is a single degree-of-freedom (DOF)mechanism, which exemplifies the shape and movement of a human leg. Theactuator of the mechanism is located in the upper portion of the linkagesimilar to it in a human leg. The mechanism is simulated and tested to verifythe proposed synthesis. A 3D model of the proposed system has been elaboratedin Solid Works®, booth for design and simulation purposes. Simulation resultsshow that the proposed mechanism performs movements similar to those of a humanleg. Maple and Adams software packages are used to simulate and validate the usabilityof the mechanism. The proposed mechanism demonstrates that a one DOF closedloop mechanical linkage can be designed to the shape and movement of the bipedhuman walking apparatus. The proposed mechanism is suitable for the fabricationof legged robots. Proportions of the linkage are estimated utilizinganthropometric measures of the human leg.

We advocate the effectiveness of a walking robot to have a structure with a reduced DOF, not based on a model of real animals, to make the robot lightweight and practical, and discuss a technique for reducing the active degrees of freedom (DOF) of a quadruped walking robot as an example for realizing such objectives. If functions required of a quadruped walking robot are properly organized and the required active DOF is examined, 4 active DOF make it possible to select an arbitrary position on uneven terrain and to move in all directions. We describe a mechanism with 4 active DOF and 2 passive DOF as an example of concrete configurations for quadruped walking robots with 4 active DOF. A robot with a reduced active DOF, namely with 3 active DOF and 2 passive DOF, has a capability to reach an arbitrary position at an arbitrary angle on uneven terrain. An actual mechanical model was manufactured as an experimental model, and a walking experiment was conducted. The mechanical model turned out to be about one-4th in weight compared to a conventional biomimetic model of the same size. Based on the walking experiment, it was confirmed that this mechanical model can carry a load up to 4 times its own weight.

The aim of this paper is to develop and validate the mathematical model of the human lower limb based on Denavit-Hartenberg (D-H) robotics convention. The proposed geometric model has 7 degrees of freedom (DOF) (3 DOF in hip joint, 2 DOF in knee joint, and 2 DOF in ankle joint). The fixed reference system was placed in the weight centre of the human body. The input data for the model are the angle variations and anthropometric parameters of the lower limb. The angle variations can be defined or imported from a gait analysis system. The anthropometric parameters were introduced from the literature. The model can be adapted to both left and right lower limb. The geometric model was solved in MATLAB environment. The model validation was individually realized taking into account the normal range of motion (ROM) of each joint.

Enhancing energy efficiency of bipedal walking is an important research problem that has been approached by design of recently developed compliant bipedal robots such as CoMan. While compliance leads to energy efficiency, it also complicates the walking control system due to further under-actuated degrees of freedom (DoF) associated with the compliant actuators. This problem becomes more challenging as the constrained motion of the robot in double support is considered. In this paper this problem is approached from a multi-variable geometric control aspect to systematically account for the compliant actuators dynamics and constrained motion of the robot in double support phase using a detailed electro-mechanical model of CoMan. It is shown that the formulation of constraint subspace is non-trivial in the case of non-rigid robots. A step-wise numerical algorithm is provided and the effectiveness of the proposed method is illustrated via simulation, using a ten DoF model of CoMan.

Designing a humanoid robot is a complex issue and the exact resemblance of human arm movements has not been achieved in many of the previously developed robots. This paper is going to be much focused on the design of a humanoid robot arm which has a unique approach which has never been developed earlier. Even though all the robots that have been developed using 6-Degrees of Freedom (DOF) and 7-DOF can reach any point in the space, some of the orientation cannot be reached by the end effector plane effectively. So an 8-DOF freedom based robotic arm has been specially designed and developed to resemble the exact movements of the human being. This robot has 3-DOF for shoulder joint, 2-DOF for the elbow joint, and 3-DOF for the wrist with fingers as the end effector. Almost all the robots have only 1-DOF to the elbow joint but here 2-DOF has been proposed to resemble the exact movements of the human being (2-DOF at elbow) to solve the above mentioned problem. Literature reviews and design model are discussed in detail to support the proposal that has been made. Forward and inverse Kinematic relationships are also obtained for the joint link parameter. This humanoid robot arm which has been designed and developed is one of the modules of a human size humanoid robot RALA (Robot based on Autonomous Learning Algorithm).

Walking comes naturally to us and appears to be simple. However, this is not so and it is known that walking requires high level neural control and muscle coordination. There is no single, unifying theory of bipedal walking. Models of walking are useful in various ways such as developing computational theories of neural control, understanding muscle coordination and to design and analyze lower extremity prostheses. This thesis deals with modeling and simulation of walking from a kinematics and dynamics view point. Three sagittal planar models with increasing levels of complexity are presented in this thesis. The first model is a simple two degrees of freedom (DoF) model representing the motion at the hip and the knee joint. The second model is a three DoF model where the ankle joint motion is also taken into account. Finally, the third model considers both the legs and has seven DoF. The kinematic and dynamic equations of the models are derived, and the inverse dynamic analysis and forward dynamic simulation of the models are performed. The simulation results are compared with experimental data available in literature.

Walking comes naturally to us and appears to be simple. However, this is not so and it is known that walking requires high level neural control and muscle coordination. There is no single, unifying theory of bipedal walking. Models of walking are useful in various ways such as developing computational theories of neural control, understanding muscle coordination and to design and analyze lower extremity prostheses. This thesis deals with modeling and simulation of walking from a kinematics and dynamics view point. Three sagittal planar models with increasing levels of complexity are presented in this thesis. The first model is a simple two degrees of freedom (DoF) model representing the motion at the hip and the knee joint. The second model is a three DoF model where the ankle joint motion is also taken into account. Finally, the third model considers both the legs and has seven DoF. The kinematic and dynamic equations of the models are derived, and the inverse dynamic analysis and forward dynamic simulation of the models are performed. The simulation results are compared with experimental data available in literature.

Nationalism: Past as Prologue began as a single volume being compiled by Ad Akande, a scholar from South Africa, who proposed it to me as co-author about two years ago. The original idea was to examine how the damaging roots of nationalism have been corroding political systems around the world, and creating dangerous obstacles for necessary international cooperation. Since I (Bruce E. Johansen) has written profusely about climate change (global warming, a.k.a. infrared forcing), I suggested a concerted effort in that direction. This is a worldwide existential threat that affects every living thing on Earth. It often compounds upon itself, so delays in reducing emissions of fossil fuels are shortening the amount of time remaining to eliminate the use of fossil fuels to preserve a livable planet. Nationalism often impedes solutions to this problem (among many others), as nations place their singular needs above the common good. Our initial proposal got around, and abstracts on many subjects arrived. Within a few weeks, we had enough good material for a 100,000-word book. The book then fattened to two moderate volumes and then to four two very hefty tomes. We tried several different titles as good submissions swelled. We also discovered that our best contributors were experts in their fields, which ranged the world. We settled on three stand-alone books:” 1/ nationalism and racial justice. Our first volume grew as the growth of Black Lives Matter following the brutal killing of George Floyd ignited protests over police brutality and other issues during 2020, following the police assassination of Floyd in Minneapolis. It is estimated that more people took part in protests of police brutality during the summer of 2020 than any other series of marches in United States history. This includes upheavals during the 1960s over racial issues and against the war in Southeast Asia (notably Vietnam). We choose a volume on racism because it is one of nationalism’s main motive forces. This volume provides a worldwide array of work on nationalism’s growth in various countries, usually by authors residing in them, or in the United States with ethnic ties to the nation being examined, often recent immigrants to the United States from them. Our roster of contributors comprises a small United Nations of insightful, well-written research and commentary from Indonesia, New Zealand, Australia, China, India, South Africa, France, Portugal, Estonia, Hungary, Russia, Poland, Kazakhstan, Georgia, and the United States. Volume 2 (this one) describes and analyzes nationalism, by country, around the world, except for the United States; and 3/material directly related to President Donald Trump, and the United States. The first volume is under consideration at the Texas A & M University Press. The other two are under contract to Nova Science Publishers (which includes social sciences). These three volumes may be used individually or as a set. Environmental material is taken up in appropriate places in each of the three books. * * * * * What became the United States of America has been strongly nationalist since the English of present-day Massachusetts and Jamestown first hit North America’s eastern shores. The country propelled itself across North America with the self-serving ideology of “manifest destiny” for four centuries before Donald Trump came along. Anyone who believes that a Trumpian affection for deportation of “illegals” is a new thing ought to take a look at immigration and deportation statistics in Adam Goodman’s The Deportation Machine: America’s Long History of Deporting Immigrants (Princeton University Press, 2020). Between 1920 and 2018, the United States deported 56.3 million people, compared with 51.7 million who were granted legal immigration status during the same dates. Nearly nine of ten deportees were Mexican (Nolan, 2020, 83). This kind of nationalism, has become an assassin of democracy as well as an impediment to solving global problems. Paul Krugman wrote in the New York Times (2019:A-25): that “In their 2018 book, How Democracies Die, the political scientists Steven Levitsky and Daniel Ziblatt documented how this process has played out in many countries, from Vladimir Putin’s Russia, to Recep Erdogan’s Turkey, to Viktor Orban’s Hungary. Add to these India’s Narendra Modi, China’s Xi Jinping, and the United States’ Donald Trump, among others. Bit by bit, the guardrails of democracy have been torn down, as institutions meant to serve the public became tools of ruling parties and self-serving ideologies, weaponized to punish and intimidate opposition parties’ opponents. On paper, these countries are still democracies; in practice, they have become one-party regimes….And it’s happening here [the United States] as we speak. If you are not worried about the future of American democracy, you aren’t paying attention” (Krugmam, 2019, A-25). We are reminded continuously that the late Carl Sagan, one of our most insightful scientific public intellectuals, had an interesting theory about highly developed civilizations. Given the number of stars and planets that must exist in the vast reaches of the universe, he said, there must be other highly developed and organized forms of life. Distance may keep us from making physical contact, but Sagan said that another reason we may never be on speaking terms with another intelligent race is (judging from our own example) could be their penchant for destroying themselves in relatively short order after reaching technological complexity. This book’s chapters, introduction, and conclusion examine the worldwide rise of partisan nationalism and the damage it has wrought on the worldwide pursuit of solutions for issues requiring worldwide scope, such scientific co-operation public health and others, mixing analysis of both. We use both historical description and analysis. This analysis concludes with a description of why we must avoid the isolating nature of nationalism that isolates people and encourages separation if we are to deal with issues of world-wide concern, and to maintain a sustainable, survivable Earth, placing the dominant political movement of our time against the Earth’s existential crises. Our contributors, all experts in their fields, each have assumed responsibility for a country, or two if they are related. This work entwines themes of worldwide concern with the political growth of nationalism because leaders with such a worldview are disinclined to co-operate internationally at a time when nations must find ways to solve common problems, such as the climate crisis. Inability to cooperate at this stage may doom everyone, eventually, to an overheated, stormy future plagued by droughts and deluges portending shortages of food and other essential commodities, meanwhile destroying large coastal urban areas because of rising sea levels. Future historians may look back at our time and wonder why as well as how our world succumbed to isolating nationalism at a time when time was so short for cooperative intervention which is crucial for survival of a sustainable earth. Pride in language and culture is salubrious to individuals’ sense of history and identity. Excess nationalism that prevents international co-operation on harmful worldwide maladies is quite another. As Pope Francis has pointed out: For all of our connectivity due to expansion of social media, ability to communicate can breed contempt as well as mutual trust. “For all our hyper-connectivity,” said Francis, “We witnessed a fragmentation that made it more difficult to resolve problems that affect us all” (Horowitz, 2020, A-12). The pope’s encyclical, titled “Brothers All,” also said: “The forces of myopic, extremist, resentful, and aggressive nationalism are on the rise.” The pope’s document also advocates support for migrants, as well as resistance to nationalist and tribal populism. Francis broadened his critique to the role of market capitalism, as well as nationalism has failed the peoples of the world when they need co-operation and solidarity in the face of the world-wide corona virus pandemic. Humankind needs to unite into “a new sense of the human family [Fratelli Tutti, “Brothers All”], that rejects war at all costs” (Pope, 2020, 6-A). Our journey takes us first to Russia, with the able eye and honed expertise of Richard D. Anderson, Jr. who teaches as UCLA and publishes on the subject of his chapter: “Putin, Russian identity, and Russia’s conduct at home and abroad.” Readers should find Dr. Anderson’s analysis fascinating because Vladimir Putin, the singular leader of Russian foreign and domestic policy these days (and perhaps for the rest of his life, given how malleable Russia’s Constitution has become) may be a short man physically, but has high ambitions. One of these involves restoring the old Russian (and Soviet) empire, which would involve re-subjugating a number of nations that broke off as the old order dissolved about 30 years ago. President (shall we say czar?) Putin also has international ambitions, notably by destabilizing the United States, where election meddling has become a specialty. The sight of Putin and U.S. president Donald Trump, two very rich men (Putin $70-$200 billion; Trump $2.5 billion), nuzzling in friendship would probably set Thomas Jefferson and Vladimir Lenin spinning in their graves. The road of history can take some unanticipated twists and turns. Consider Poland, from which we have an expert native analysis in chapter 2, Bartosz Hlebowicz, who is a Polish anthropologist and journalist. His piece is titled “Lawless and Unjust: How to Quickly Make Your Own Country a Puppet State Run by a Group of Hoodlums – the Hopeless Case of Poland (2015–2020).” When I visited Poland to teach and lecture twice between 2006 and 2008, most people seemed to be walking on air induced by freedom to conduct their own affairs to an unusual degree for a state usually squeezed between nationalists in Germany and Russia. What did the Poles then do in a couple of decades? Read Hlebowicz’ chapter and decide. It certainly isn’t soft-bellied liberalism. In Chapter 3, with Bruce E. Johansen, we visit China’s western provinces, the lands of Tibet as well as the Uighurs and other Muslims in the Xinjiang region, who would most assuredly resent being characterized as being possessed by the Chinese of the Han to the east. As a student of Native American history, I had never before thought of the Tibetans and Uighurs as Native peoples struggling against the Independence-minded peoples of a land that is called an adjunct of China on most of our maps. The random act of sitting next to a young woman on an Air India flight out of Hyderabad, bound for New Delhi taught me that the Tibetans had something to share with the Lakota, the Iroquois, and hundreds of other Native American states and nations in North America. Active resistance to Chinese rule lasted into the mid-nineteenth century, and continues today in a subversive manner, even in song, as I learned in 2018 when I acted as a foreign adjudicator on a Ph.D. dissertation by a Tibetan student at the University of Madras (in what is now in a city called Chennai), in southwestern India on resistance in song during Tibet’s recent history. Tibet is one of very few places on Earth where a young dissident can get shot to death for singing a song that troubles China’s Quest for Lebensraum. The situation in Xinjiang region, where close to a million Muslims have been interned in “reeducation” camps surrounded with brick walls and barbed wire. They sing, too. Come with us and hear the music. Back to Europe now, in Chapter 4, to Portugal and Spain, we find a break in the general pattern of nationalism. Portugal has been more progressive governmentally than most. Spain varies from a liberal majority to military coups, a pattern which has been exported to Latin America. A situation such as this can make use of the term “populism” problematic, because general usage in our time usually ties the word into a right-wing connotative straightjacket. “Populism” can be used to describe progressive (left-wing) insurgencies as well. José Pinto, who is native to Portugal and also researches and writes in Spanish as well as English, in “Populism in Portugal and Spain: a Real Neighbourhood?” provides insight into these historical paradoxes. Hungary shares some historical inclinations with Poland (above). Both emerged from Soviet dominance in an air of developing freedom and multicultural diversity after the Berlin Wall fell and the Soviet Union collapsed. Then, gradually at first, right wing-forces began to tighten up, stripping structures supporting popular freedom, from the courts, mass media, and other institutions. In Chapter 5, Bernard Tamas, in “From Youth Movement to Right-Liberal Wing Authoritarianism: The Rise of Fidesz and the Decline of Hungarian Democracy” puts the renewed growth of political and social repression into a context of worldwide nationalism. Tamas, an associate professor of political science at Valdosta State University, has been a postdoctoral fellow at Harvard University and a Fulbright scholar at the Central European University in Budapest, Hungary. His books include From Dissident to Party Politics: The Struggle for Democracy in Post-Communist Hungary (2007). Bear in mind that not everyone shares Orbán’s vision of what will make this nation great, again. On graffiti-covered walls in Budapest, Runes (traditional Hungarian script) has been found that read “Orbán is a motherfucker” (Mikanowski, 2019, 58). Also in Europe, in Chapter 6, Professor Ronan Le Coadic, of the University of Rennes, Rennes, France, in “Is There a Revival of French Nationalism?” Stating this title in the form of a question is quite appropriate because France’s nationalistic shift has built and ebbed several times during the last few decades. For a time after 2000, it came close to assuming the role of a substantial minority, only to ebb after that. In 2017, the candidate of the National Front reached the second round of the French presidential election. This was the second time this nationalist party reached the second round of the presidential election in the history of the Fifth Republic. In 2002, however, Jean-Marie Le Pen had only obtained 17.79% of the votes, while fifteen years later his daughter, Marine Le Pen, almost doubled her father's record, reaching 33.90% of the votes cast. Moreover, in the 2019 European elections, re-named Rassemblement National obtained the largest number of votes of all French political formations and can therefore boast of being "the leading party in France.” The brutality of oppressive nationalism may be expressed in personal relationships, such as child abuse. While Indonesia and Aotearoa [the Maoris’ name for New Zealand] hold very different ranks in the United Nations Human Development Programme assessments, where Indonesia is classified as a medium development country and Aotearoa New Zealand as a very high development country. In Chapter 7, “Domestic Violence Against Women in Indonesia and Aotearoa New Zealand: Making Sense of Differences and Similarities” co-authors, in Chapter 8, Mandy Morgan and Dr. Elli N. Hayati, from New Zealand and Indonesia respectively, found that despite their socio-economic differences, one in three women in each country experience physical or sexual intimate partner violence over their lifetime. In this chapter ther authors aim to deepen understandings of domestic violence through discussion of the socio-economic and demographic characteristics of theit countries to address domestic violence alongside studies of women’s attitudes to gender norms and experiences of intimate partner violence. One of the most surprising and upsetting scholarly journeys that a North American student may take involves Adolf Hitler’s comments on oppression of American Indians and Blacks as he imagined the construction of the Nazi state, a genesis of nationalism that is all but unknown in the United States of America, traced in this volume (Chapter 8) by co-editor Johansen. Beginning in Mein Kampf, during the 1920s, Hitler explicitly used the westward expansion of the United States across North America as a model and justification for Nazi conquest and anticipated colonization by Germans of what the Nazis called the “wild East” – the Slavic nations of Poland, the Baltic states, Ukraine, and Russia, most of which were under control of the Soviet Union. The Volga River (in Russia) was styled by Hitler as the Germans’ Mississippi, and covered wagons were readied for the German “manifest destiny” of imprisoning, eradicating, and replacing peoples the Nazis deemed inferior, all with direct references to events in North America during the previous century. At the same time, with no sense of contradiction, the Nazis partook of a long-standing German romanticism of Native Americans. One of Goebbels’ less propitious schemes was to confer honorary Aryan status on Native American tribes, in the hope that they would rise up against their oppressors. U.S. racial attitudes were “evidence [to the Nazis] that America was evolving in the right direction, despite its specious rhetoric about equality.” Ming Xie, originally from Beijing, in the People’s Republic of China, in Chapter 9, “News Coverage and Public Perceptions of the Social Credit System in China,” writes that The State Council of China in 2014 announced “that a nationwide social credit system would be established” in China. “Under this system, individuals, private companies, social organizations, and governmental agencies are assigned a score which will be calculated based on their trustworthiness and daily actions such as transaction history, professional conduct, obedience to law, corruption, tax evasion, and academic plagiarism.” The “nationalism” in this case is that of the state over the individual. China has 1.4 billion people; this system takes their measure for the purpose of state control. Once fully operational, control will be more subtle. People who are subject to it, through modern technology (most often smart phones) will prompt many people to self-censor. Orwell, modernized, might write: “Your smart phone is watching you.” Ming Xie holds two Ph.Ds, one in Public Administration from University of Nebraska at Omaha and another in Cultural Anthropology from the Chinese Academy of Social Sciences, Beijing, where she also worked for more than 10 years at a national think tank in the same institution. While there she summarized news from non-Chinese sources for senior members of the Chinese Communist Party. Ming is presently an assistant professor at the Department of Political Science and Criminal Justice, West Texas A&M University. In Chapter 10, analyzing native peoples and nationhood, Barbara Alice Mann, Professor of Honours at the University of Toledo, in “Divide, et Impera: The Self-Genocide Game” details ways in which European-American invaders deprive the conquered of their sense of nationhood as part of a subjugation system that amounts to genocide, rubbing out their languages and cultures -- and ultimately forcing the native peoples to assimilate on their own, for survival in a culture that is foreign to them. Mann is one of Native American Studies’ most acute critics of conquests’ contradictions, and an author who retrieves Native history with a powerful sense of voice and purpose, having authored roughly a dozen books and numerous book chapters, among many other works, who has traveled around the world lecturing and publishing on many subjects. Nalanda Roy and S. Mae Pedron in Chapter 11, “Understanding the Face of Humanity: The Rohingya Genocide.” describe one of the largest forced migrations in the history of the human race, the removal of 700,000 to 800,000 Muslims from Buddhist Myanmar to Bangladesh, which itself is already one of the most crowded and impoverished nations on Earth. With about 150 million people packed into an area the size of Nebraska and Iowa (population less than a tenth that of Bangladesh, a country that is losing land steadily to rising sea levels and erosion of the Ganges river delta. The Rohingyas’ refugee camp has been squeezed onto a gigantic, eroding, muddy slope that contains nearly no vegetation. However, Bangladesh is majority Muslim, so while the Rohingya may starve, they won’t be shot to death by marauding armies. Both authors of this exquisite (and excruciating) account teach at Georgia Southern University in Savannah, Georgia, Roy as an associate professor of International Studies and Asian politics, and Pedron as a graduate student; Roy originally hails from very eastern India, close to both Myanmar and Bangladesh, so he has special insight into the context of one of the most brutal genocides of our time, or any other. This is our case describing the problems that nationalism has and will pose for the sustainability of the Earth as our little blue-and-green orb becomes more crowded over time. The old ways, in which national arguments often end in devastating wars, are obsolete, given that the Earth and all the people, plants, and other animals that it sustains are faced with the existential threat of a climate crisis that within two centuries, more or less, will flood large parts of coastal cities, and endanger many species of plants and animals. To survive, we must listen to the Earth, and observe her travails, because they are increasingly our own.

Long drives on bumpy roads and configuration issues like discomfort in seating arrangements have a harmful impact on the human body. The passengers experience severe health problems and stress-related issues. The full car model (FCM) with seven degrees of freedom (DOF) is considered for vibration control analysis. The aim of this work is to optimize the parameters of proportional integral and derivative (PID) controller by grey wolf optimization (GWO) and bat algorithm for betterment in the ride comfort of the passengers. A comparative analysis between the most commonly used PID controller and proposed optimized PID controller was executed over bump input (BI), ISO standard random input (RI), and sinusoidal input (SI) road profiles in MATLAB. Simulation results demonstrate that bat tuned PID (Bat-PID) controller enhances the ride comfort by decreasing the root mean square (RMS), frequency weighted RMS (FWRMS), and vibration dose values (VDV) of the body acceleration (BA) of the vehicle passing over BI, RI, and SI road profiles, which ensures the stability of the vehicle.

Cyclic human gait is simulated in this work by using a 2D musculoskeletal model with 12 degrees of freedom (DOF). Eight muscle groups are modeled on each leg. Predictive dynamics approach is used to predict the walking motion. In this process, the model predicts joints dynamics and muscle forces simultaneously using optimization schemes and task-based physical constraints. The results indicated that the model can realistically match human motion, ground reaction forces (GRF), and muscle force data during walking task. The proposed optimization algorithm is robust and the optimal solution is obtained in seconds. This can be used in human health domain such as leg prosthesis design.

Foot-ground interaction is modeled for a human gait simulation by using a 2D skeletal model with 12 degrees of freedom (DOF). Three contacting elements are attached to the heel, phalangeal, and toe sections respectively. The contacting process is modeled using an inverse optimization approach, in which the contacting force due to the penetration deformation and velocity is equal to the balanced ground reaction force (GRF). This is set as an equality constraint in the walking optimization formulation. A predictive dynamics approach is used to predict the walking motion and to optimize the contacting process. The results indicated that the contacting model can realistically match the GRF, and the resulting gait motion, contacting penetration, and contacting parameters are all optimized simultaneously. The optimal solution is obtained in seconds. This demonstrates an efficient way to model the foot-ground contacting deformation process using an inverse optimization method and eliminates the need for integrating equations of motion (EOM).

Pregnant women’s size, shape, and weight changes have significant effects on their walking stability. Traditionally, experiments are used to study the effects of subjects, but it is time consuming and expensive. This paper presents an optimization-based pregnant women walking simulation with one-stride formulation. The pregnant woman’s model with 55 degrees of freedom (DOFs) is used, including 6 global DOF’s and 49 human body DOF’s. The dynamic equations of motion are based on the recursive dynamics. Without the constraint of symmetry of the human body between two steps within one walking cycle, the study is based on bio-mechanical, human kinematic, and dynamic properties to perform the one-stride simulation, which represent the holonomic and non-holonomic constraints in walking simulation. This forms a nonlinear optimization problem. The summation of all joint actuator torques squared within one stride is the cost function. Nine determinant DOF’s are used to analyze the kinematics and three for dynamics. Three cases (non-pregnancy, 6 month, and 9 month pregnancy) are adopted for the test and investigation. The simulation results show that during the course of pregnancy, pregnant women’s bodies dynamic and kinematic properties change and thus affect their walking and stability.

This paper presents a new biped humanoid robot, as well as control strategies to be implemented for walking and balance recovery. The ultimate design goal was to design the structure to be as close to a lower part of human body as possible. Therefore, golden-ratio-based human body proportions and proper number of degrees of freedom of the lower part are used [1]. The biped has 12 actuated DOE in the lower body: three at each hip, one at each knee, two at each ankle as well as 1 additional DOF at its torso. Each degree of freedom is powered by a force controllable actuator. To achieve human like trajectory, human walking data has been used [2]. To insure both stability and human like trajectory, a torque compensator is added to the one DOF at the torso. The Biped is designed in SolidWorks and simulated in SimMechanic and COSMOSMotion. The movement of the joints are achieved by motors and harmonic drives. The contact between sole and ground is considered to be elastic and is modelled using spring and damper in horizontal and vertical directions [3]. Finally, control of the biped is performed using a PID control scheme and each of the 13 motors achieve desired human like trajectory.

An objective of this study is to simulate the backward walking motion of a full-body digital human model. The model consists of 55 degree of freedom – 6 degrees of freedom for global translation and rotation and 49 degrees of freedom representing the kinematics of the entire body. The resultant action of all the muscles at a joint is represented by the torque for each degree of freedom. The torques and angles at a joint are treated as unknowns in the optimization problem. The B-spline interpolation is used to represent the time histories of the joint angles and the well-established robotics formulation of the Denavit-Hartenberg method is used for kinematics analysis of the mechanical system. The recursive Lagrangian formulation is used to develop the equations of motion, and was chosen because of its known computational efficiency. The backwards walking problem is formulated as a nonlinear optimization problem. The control points of the B-splines for the joint angle profiles are treated as the design variables. For the performance measure, total dynamic effort that is represented as the integral of the sum of the squares of all the joint torques is minimized using a sequential quadratic programming algorithm. The solution is simulated in the Santos™ environment. Results of the optimization problem are the torque and joint angle profiles. The torques at the key joints and the ground reaction forces are compared to those for the forward walk in order to study the differences between the two walking patterns. Simulation results are approximately validated with the experimental data which is motion captured in the VSR Lab at the University of Iowa.

The human ankle plays a major role in locomotion as it the first major joint to transfer the ground reaction torques to the rest of the body while providing power for locomotion and stability. One of the main causes of the ankle impedance modulation is muscle activation [1, 2], which can tune the ankle’s stiffness and damping during the stance phase of gait. The ankle’s time-varying impedance is also task dependent, meaning that different activities such as walking at different speeds, turning, and climbing/descending stairs would impose different profiles of time-varying impedance modulation. The impedance control is commonly used in the control of powered ankle-foot prostheses; however, the information on time-varying impedance of the ankle during the stance phase is limited in the literature. The only previous study during the stance phase, to the best of the authors knowledge, reported the human ankle impedance at four points of the stance phase in dorsiflexion-plantarflexion (DP) [1] during walking. To expand previous work and estimate the impedance in inversion-eversion (IE), a vibrating platform was fabricated (Fig. 1) [3]. The platform allows the ankle impedance to be estimated at 250 Hz in both DP and IE, including combined rotations in both degrees of freedom (DOF) simultaneously. The results can be used in a 2-DOF powered ankle-foot prosthesis developed by the authors, which is capable of mimicking the ankle kinetics and kinematics in the frontal and sagittal planes [4]. The vibrating platform can also be used to tune the prosthesis to assure it properly mimics the human ankle dynamics. This paper describes the results of the preliminary experiments using the vibrating platform on 4 male subjects. For the first time, the time-varying impedance of the human ankle in both DP and IE during walking in a straight line are reported.

3D equipment interaction module in human motion simulation is developed in this paper. A predictive dynamics method is used to simulate human motion, and a helmet is modeled as the equipment that is attached to the human body. We then implement this method using the predictive dynamics task of walking. A mass-spring-damper system is attached at the top of the head as a helmet model. The equations of motion for the helmet are also derived in a recursive Lagrangian formulation within the same inertial reference frame as the human model’s. The total number of degrees of freedom for the human model is 55 — 6 degrees of freedom for global translation and rotation, and 49 degrees of freedom for the body. The helmet has 7 degrees of freedom, but 6 of them are dependent to the human model. The movement of the helmet is analyzed due to the human motion. Then, the reaction force between the human body and the equipment is calculated. Once the reaction force is obtained, it is applied to the human body as an external force in the predictive dynamics optimization process. Results include the motion of equipment, the force acting on body at the attachment point, the joint torque profiles, and the ground reaction force profiles at the foot contacting point.

This paper presents a novel 6-URS self-reconfigurable all-dimensional walking robot. The model of the 6-URS self-reconfigurable walking robot is established, then its reconfiguration modes are proposed. Based on the screw theory, the degrees of freedom (DOF) of this robot before and after reconfiguration are analysed separately to verify the feasibility of self-reconfiguration. This robot can achieve self-reconfigurable function with the design of self-reconfigurable limbs. Moreover, the trajectory planning and simulation of three kinds of gaits are performed, including walking horizontally, turning and climbing. The above analysis shows that the 6-URS self-reconfigurable all-dimensional robot satisfies the walking requirements and has the reconfigurable ability in unstrcutured environment.

Typically, MultiBody Dynamics (MBD) simulations of the human hip use 3 degrees of freedom to represent joint constraints. Consequently, typical MBD simulations omit the important characteristic of cartilage deformation. This paper presents a novel development of a surface-to-surface contact model that allows for an improved understanding of joint mechanics during dynamic activities such as walking. The contact model uses bilateral constraints, whereby the cartilage mechanical properties are derived from Finite Element (FE) and experimental investigations. Future developments will use this new technique for modeling the hip in order to help clinicians understand how movement sequences may cause severe deformations, and so clinicians can then advise patients to avoid activities that increase the risk of wear and degeneration.

This paper describes in detail the fabrication of an instrumented walkway for estimation of the ankle mechanical impedance in both dorsiflexion-plantarflexion (DP) and in inversion-eversion (IE) directions during walking in arbitrary directions and standing. The platform consists of two linear actuators, each capable of generating ±351.3 N peak force that are mechanically coupled to a force plate using Bowden cables. The applied forces cause the force plate to rotate in two degrees of freedom (DOF) and transfer torques to the human ankle to generate DP and IE rotations. The relative rotational motion of the foot with respect to the shin is recorded using a motion capture camera system while the forces applied to the foot are measured with the force plate, from which the torques applied to the ankle are calculated. The analytical methods required for the estimation of the ankle torques, rotations, and impedances are presented. To validate the system, a mockup with known stiffness was used, and it was shown that the developed system was capable of properly estimating the stiffness of the mockup in two DOF with less than 5% error. Also, a preliminary experiment with a human subject in standing position was performed, and the estimated quasi-static impedance of the ankle was estimated at 319 Nm/rad in DP and 119 Nm/rad in IE.