Bipedalism is a form of terrestrial locomotion where a tetrapod moves by means of its two rear limbs or legs. An animal or machine that usually moves in a bipedal manner is known as a biped, meaning 'two feet'. Types of bipedal movement include walking or running and hopping.
Walking is one of the main gaits of terrestrial locomotion among legged animals. Walking is typically slower than running and other gaits. Walking is defined by an 'inverted pendulum' gait in which the body vaults over the stiff limb or limbs with each step. This applies regardless of the usable number of limbs—even arthropods, with six, eight, or more limbs, walk.
Gait is the pattern of movement of the limbs of animals, including humans, during locomotion over a solid substrate. Most animals use a variety of gaits, selecting gait based on speed, terrain, the need to maneuver, and energetic efficiency. Different animal species may use different gaits due to differences in anatomy that prevent use of certain gaits, or simply due to evolved innate preferences as a result of habitat differences. While various gaits are given specific names, the complexity of biological systems and interacting with the environment make these distinctions "fuzzy" at best. Gaits are typically classified according to footfall patterns, but recent studies often prefer definitions based on mechanics. The term typically does not refer to limb-based propulsion through fluid mediums such as water or air, but rather to propulsion across a solid substrate by generating reactive forces against it.
A gait is a manner of limb movements made during locomotion. Human gaits are the various ways in which humans can move, either naturally or as a result of specialized training. Human gait is defined as bipedal forward propulsion of the center of gravity of the human body, in which there are sinuous movements of different segments of the body with little energy spent. Varied gaits are characterized by differences such as limb movement patterns, overall velocity, forces, kinetic and potential energy cycles, and changes in contact with the ground.
Robot locomotion is the collective name for the various methods that robots use to transport themselves from place to place.
SIGMO is a humanoid robot designed to demonstrate the applications of passive dynamics technologies.
Terrestrial locomotion has evolved as animals adapted from aquatic to terrestrial environments. Locomotion on land raises different problems than that in water, with reduced friction being replaced by the increased effects of gravity.
Legged robots are a type of mobile robot which use articulated limbs, such as leg mechanisms, to provide locomotion. They are more versatile than wheeled robots and can traverse many different terrains, though these advantages require increased complexity and power consumption. Legged robots often imitate legged animals, such as humans or insects, in an example of biomimicry.
RunBot is a miniature bipedal robot which belongs to the class of limit cycle walkers. Instead of using a central pattern generator it uses reflexes which generate the gait. The reflexes are triggered by ground contact sensors in the feet which then activate the motors. The generation of the walking gait is straightforward: when a foot touches the ground the other leg is lifted upwards so that the robot falls forward. This then causes this leg to touch the ground and so forth. The walking speed can be improved by means of reinforcement learning because there are only a few parameters in this scheme. RunBot was built in 2005 by Tao Geng as part of his PhD under supervision of Prof Woergoetter and after an idea by Dr Porr to use a walking robot to benchmark reflex based reinforcement learning rules. Its movements and adaptability are based on the work of neurophysiologist Nikolai Bernstein.
The evolution of human bipedalism, which began in primates approximately four million years ago, or as early as seven million years ago with Sahelanthropus, or approximately twelve million years ago with Danuvius guggenmosi, has led to morphological alterations to the human skeleton including changes to the arrangement, shape, and size of the bones of the foot, hip, knee, leg, and the vertebral column. These changes allowed for the upright gait to be overall more energy efficient in comparison to quadrupeds. The evolutionary factors that produced these changes have been the subject of several theories that correspond with environmental changes on a global scale.
Robotics is an interdisciplinary branch of Electronics & Communication, computer science and engineering. Robotics involves the design, construction, operation, and use of robots. The goal of robotics is to design machines that can help and assist humans. Robotics integrates fields of mechanical engineering, electrical engineering, information engineering, mechatronics engineering, electronics, biomedical engineering, computer engineering, control systems engineering, software engineering, mathematics, etc.
Orthotics is a medical specialty that focuses on the design and application of orthoses, or braces. An orthosis is "an externally applied device used to influence the structural and functional characteristics of the neuromuscular and skeletal systems."
A powered exoskeleton, also known as power armor, powered armor, powered suit, cybernetic suit, cybernetic armor, exosuit, hardsuit, exoframe or augmented mobility, is a mobile machine that is wearable over all or part of the human body, providing ergonomic structural support and powered by a system of electric motors, pneumatics, levers, hydraulics or a combination of cybernetic technologies, while allowing for sufficient limb movement with increased strength and endurance. The exoskeleton is designed to provide better mechanical load tolerance, and its control system aims to sense and synchronize with the user's intended motion and relay the signal to motors which manage the gears. The exoskeleton also protects the user's shoulder, waist, back and thigh against overload, and stabilizes movements when lifting and holding heavy items.
Bio-inspired robotic locomotion is a fairly new subcategory of bio-inspired design. It is about learning concepts from nature and applying them to the design of real-world engineered systems. More specifically, this field is about making robots that are inspired by biological systems, including Biomimicry. Biomimicry is copying from nature while bio-inspired design is learning from nature and making a mechanism that is simpler and more effective than the system observed in nature. Biomimicry has led to the development of a different branch of robotics called soft robotics. The biological systems have been optimized for specific tasks according to their habitat. However, they are multifunctional and are not designed for only one specific functionality. Bio-inspired robotics is about studying biological systems, and looking for the mechanisms that may solve a problem in the engineering field. The designer should then try to simplify and enhance that mechanism for the specific task of interest. Bio-inspired roboticists are usually interested in biosensors, bioactuators, or biomaterials. Most of the robots have some type of locomotion system. Thus, in this article different modes of animal locomotion and few examples of the corresponding bio-inspired robots are introduced.
Arm swing in human bipedal walking is a natural motion wherein each arm swings with the motion of the opposing leg. Swinging arms in an opposing direction with respect to the lower limb reduces the angular momentum of the body, balancing the rotational motion produced during walking. Although such pendulum-like motion of arms is not essential for walking, recent studies point that arm swing improves the stability and energy efficiency in human locomotion. Those positive effects of arm swing have been utilized in sports, especially in racewalking and sprinting.
The effect of gait parameters on energetic cost is a relationship that describes how changes in step length, cadence, step width, and step variability influence the mechanical work and metabolic cost involved in gait. The source of this relationship stems from the deviation of these gait parameters from metabolically optimal values, with the deviations due to environmental, pathological, and other factors.
MABEL is a robot engineered in 2009 by researchers at the University of Michigan, which is well known for being the world's fastest bipedal (two-legged) robot with knees. MABEL is able to reach speeds of up to 3.6 m/s (6.8 mph). The name MABEL is an acronym for Michigan Anthropomorphic Biped With Electronic Legs. The creators include J.W. Grizzle, Jonathan Hurst, Hae-Won Park, Koushil Sreenath, and Alireza Ramezani. MABEL weighs 143 pounds with most of its weight being in the top torso area. The legs contain large springs and are jointed to form knees. The robot is attached to a safety boom for lateral stability.
Robotic prosthesis control is a method for controlling a prosthesis in such a way that the controlled robotic prosthesis restores a biologically accurate gait to a person with a loss of limb. This is a special branch of control that has an emphasis on the interaction between humans and robotics.
Gait deviations are nominally referred to as any variation of standard human gait, typically manifesting as a coping mechanism in response to an anatomical impairment. Lower-limb amputees are unable to maintain the characteristic walking patterns of an able-bodied individual due to the removal of some portion of the impaired leg. Without the anatomical structure and neuromechanical control of the removed leg segment, amputees must use alternative compensatory strategies to walk efficiently. Prosthetic limbs provide support to the user and more advanced models attempt to mimic the function of the missing anatomy, including biomechanically controlled ankle and knee joints. However, amputees still display quantifiable differences in many measures of ambulation when compared to able-bodied individuals. Several common observations are whole-body movements, slower and wider steps, shorter strides, and increased sway.
The term “soft robots” designs a broad class of robotic systems whose architecture includes soft elements, with much higher elasticity than traditional rigid robots. Articulated Soft Robots are robots with both soft and rigid parts, inspired to the muscloloskeletal system of vertebrate animals – from reptiles to birds to mammalians to humans. Compliance is typically concentrated in actuators, transmission and joints while structural stability is provided by rigid or semi-rigid links.
