Locomotion Method Research Articles

A novel power-amplified jumping behavior in larval beetles (Coleoptera: Laemophloeidae).

Larval insects use many methods for locomotion. Here we describe a previously unknown jumping behavior in a group of beetle larvae (Coleoptera: Laemophloeidae). We analyze and describe this behavior in Laemophloeus biguttatus and provide information on similar observations for another laemophloeid species, Placonotus testaceus. Laemophloeus biguttatus larvae precede jumps by arching their body while gripping the substrate with their legs over a period of 0.22 ± 0.17s. This is followed by a rapid ventral curling of the body after the larvae releases its grip that launches them into the air. Larvae reached takeoff velocities of 0.47 ± 0.15 m s-1 and traveled 11.2 ± 2.8 mm (1.98 ± 0.8 body lengths) horizontally and 7.9 ± 4.3 mm (1.5 ± 0.9 body lengths) vertically during their jumps. Conservative estimates of power output revealed that some but not all jumps can be explained by direct muscle power alone, suggesting Laemophloeus biguttatus may use a latch-mediated spring actuation mechanism (LaMSA) in which interaction between the larvae's legs and the substrate serves as the latch. MicroCT scans and SEM imaging of larvae did not reveal any notable modifications that would aid in jumping. Although more in-depth experiments could not be performed to test hypotheses on the function of these jumps, we posit that this behavior is used for rapid locomotion which is energetically more efficient than crawling the same distance to disperse from their ephemeral habitat. We also summarize and discuss jumping behaviors among insect larvae for additional context of this behavior in laemophloeid beetles.

Motion of a chemically reactive bimetal motor in a magnetic field.

The wide research interest in nano-, micro-, and macromotors is due to the diverse range of applied problems in engineering, biomedicine, and ecology. At the same time, the amount of known mechanisms responsible for the locomotion of motors is limited. Here, we demonstrate a novel method of motor locomotion, which can be contingently called "chemical magnetism". The phenomenon considered here is based on the fact that any current loop in the magnetic field is affected by a force. "Chemical magnet" represents a bimetal surfer swimming at the electrolyte surface. When the redox reaction proceeds, a current loop emerges. That defines the action of the additional magnetic force on the surfer in the non-uniform magnetic field. The magnetic properties of the surfer can be varied in a wide range by changing the concentration of the electrolyte solution, its temperature, and the pair of metals composing the surfer. The phenomenon of "chemical magnetism" considered here widens a list of known mechanisms of motor locomotion.

Locomotion of Bioinspired Underwater Snake Robots Using Metaheuristic Algorithm

Snake Robots (SR) have been successfully deployed and proved to attain bio-inspired solutions owing to its capability to move in harsh environments, a characteristic not found in other kinds of robots (like wheeled or legged robots). Underwater Snake Robots (USR) establish a bioinspired solution in the domain of underwater robotics. It is a key challenge to increase the motion efficiency in underwater robots, with respect to forwarding speed, by enhancing the locomotion method. At the same time, energy efficiency is also considered as a crucial issue for long-term automation of the systems. In this aspect, the current research paper concentrates on the design of effectual Locomotion of Bioinspired Underwater Snake Robots using Metaheuristic Algorithm (LBIUSR-MA). The proposed LBIUSR-MA technique derives a bi-objective optimization problem to maximize the Forward Velocity (FV) and minimize the Average Power Consumption (APC). LBIUSR-MA technique involves the design of Manta Ray Foraging Optimization (MRFO) technique and derives two objective functions to resolve the optimization issue. In addition to these, effective weighted sum technique is also used for the integration of two objective functions. Moreover, the objective functions are required to be assessed for varying gait variables so as to inspect the performance of locomotion. A detailed set of simulation analyses was conducted and the experimental results demonstrate that the developed LBIUSR-MA method achieved a low Average Power Consumption (APC) value of 80. under δ value of 50. The proposed model accomplished the minimum PAC and maximum FV of USR in an effective manner.

Surveying a Swarm: Experimental Techniques To Establish and Examine Bacterial Collective Motion.

The survival and successful spread of many bacterial species hinges on their mode of motility. One of the most distinct of these is swarming, a collective form of motility where a dense consortium of bacteria employ flagella to propel themselves across a solid surface. Surface environments pose unique challenges, derived from higher surface friction/tension and insufficient hydration. Bacteria have adapted by deploying an array of mechanisms to overcome these challenges. Beyond allowing bacteria to colonize new terrain in the absence of bulk liquid, swarming also bestows faster speeds and enhanced antibiotic resistance to the collective. These crucial attributes contribute to the dissemination, and in some cases pathogenicity, of an array of bacteria. This minireview highlights (i) aspects of swarming motility that differentiate it from other methods of bacterial locomotion, (ii) facilitatory mechanisms deployed by diverse bacteria to overcome different surface challenges, (iii) the (often difficult) approaches required to cultivate genuine swarmers, (iv) the methods available to observe and assess the various facets of this collective motion, and (v) the features exhibited by the population as a whole.

Redirected jumping in virtual scenes with alleys

BackgroundThe redirected jumping (RDJ) technique is a new locomotion method that saves physical tracking area and enhances the body movement experience of users in virtual reality. In a previous study, the range of imperceptible manipulation gains in RDJ was discussed in an empty virtual environment (VE). MethodsIn this study, we conducted three tasks to investigate the influence of alley width on the detection threshold of jump redirection in a VE. ResultsThe results demonstrated that the imperceptible distance gain range in RDJ was not associated with the width of the alleys. The imperceptible height and rotation gain ranges in RDJ are related to the width of the alleys. ConclusionsWe preliminarily summarized the relationship between the occlusion distance and manipulation range of the three gains in a complex environment. Simultaneously, the guiding principle for choosing three gains in RDJ according to the occlusion distance in a complex environment is provided.

Convergent evolution in dippers (Aves, Cinclidae): The only wing-propelled diving songbirds.

Of the more than 6,000 members of the most speciose avian clade, Passeriformes (perching birds), only the five species of dippers (Cinclidae, Cinclus) use their wings to swim underwater. Among nonpasserine wing‐propelled divers (alcids, diving petrels, penguins, and plotopterids), convergent evolution of morphological characteristics related to this highly derived method of locomotion have been well‐documented, suggesting that the demands of this behavior exert strong selective pressure. However, despite their unique anatomical attributes, dippers have been the focus of comparatively few studies and potential convergence between dippers and nonpasseriform wing‐propelled divers has not been previously examined. In this study, a suite of characteristics that are shared among many wing‐propelled diving birds were identified and the distribution of those characteristics across representatives of all clades of extant and extinct wing‐propelled divers were evaluated to assess convergence. Putatively convergent characteristics were drawn from a relatively wide range of sources including osteology, myology, endocranial anatomy, integument, and ethology. Comparisons reveal that whereas nonpasseriform wing‐propelled divers do in fact share some anatomical characteristics putatively associated with the biomechanics of underwater “flight”, dippers have evolved this highly derived method of locomotion without converging on the majority of concomitant changes observed in other taxa. Changes in the flight musculature and feathers, reduction of the keratin bounded external nares and an increase in subcutaneous fat are shared with other wing‐propelled diving birds, but endocranial anatomy shows no significant shifts and osteological modifications are limited. Muscular and integumentary novelties may precede skeletal and neuroendocranial morphology in the acquisition of this novel locomotory mode, with implications for understanding potential biases in the fossil record of other such transitions. Thus, dippers represent an example of a highly derived and complex behavioral convergence that is not fully associated with the anatomical changes observed in other wing‐propelled divers, perhaps owing to the relative recency of their divergence from nondiving passeriforms.

An Ergonomic Assessment of Different Postures and Children Risk during Evacuations.

Crawling is recommended for avoiding high heat and toxic fumes and for obtaining more breathable air during evacuations. Few studies have evaluated the effects of crawling on physical joints and velocity, especially in children. Based on motion capture technology, this study proposes a novel method of using wearable sensors to collect exposure (e.g., mean duration, frequency) on children’s joints to objectively quantify the impacts of different locomotion methods on physical characteristics. An on-site experiment was conducted in a kindergarten with 28 children (13 boys and 15 girls) of different ages (4–6 years old) who traveled up to 22 m in three different postures: upright walking (UW), stoop walking (SW), and knee and hand crawling (KHC). The results showed that: (1) The level of joint fatigue for KHC was heavier than bipedal walking (p < 0.05), which was evidenced by higher mean duration and frequency. There was no significant difference between UW and SW (p > 0.05). (2) The physical characteristics of the children in the different postures observed in this study were different (p < 0.05). The ankle was more fatigued than other joints during bipedal walking. Unlike infants, the wrists and hips of the children became fatigued while crawling. The key actions flexion/extension are more likely to induce joint fatigue vs. other actions. (3) Crawling velocity was significantly slower than the bipedal velocities, and UW was 10.6% faster than SW (p < 0.05). The bipedal walking velocity started to decrease after the children had travelled up to 13 m, while the KHC velocity started to decrease after traveling up to 11.6 m. (4) In a severe fire, the adoption of SW is suggested, as the evacuees can both evacuate quickly and avoid overworking their joints. (5) There were no significant differences in the age (p > 0.05) and gender (p > 0.05) of the children on the joints in any of the three postures. To conclude, KHC causes more damage to body joints compared to bipedal walking, as evidenced by higher exposure (mean duration, frequency), whereas UW and SW are similar in terms of the level of joint fatigue. The above findings are expected to provide a useful reference for future applications in the children’s risk assessment and in the prevention design of buildings.

Teleportation in Virtual Reality; A Mini-Review

Teleportation is a widely implemented virtual locomotion technique that allows users to navigate beyond the confines of available tracking space with a low possibility of inducing virtual reality (VR) sickness. This paper provides a comprehensive overview of prior research on teleportation. We report results from user studies that have evaluated teleportation in comparison to other locomotion methods and survey improved versions of teleportation. We identify a number of areas for future research.

Obstacle Avoidance Path Planning for Worm-like Robot Using Bézier Curve.

Worm-like robots have demonstrated great potential in navigating through environments requiring body shape deformation. Some examples include navigating within a network of pipes, crawling through rubble for search and rescue operations, and medical applications such as endoscopy and colonoscopy. In this work, we developed path planning optimization techniques and obstacle avoidance algorithms for the peristaltic method of locomotion of worm-like robots. Based on our previous path generation study using a modified rapidly exploring random tree (RRT), we have further introduced the Bézier curve to allow more path optimization flexibility. Using Bézier curves, the path planner can explore more areas and gain more flexibility to make the path smoother. We have calculated the obstacle avoidance limitations during turning tests for a six-segment robot with the developed path planning algorithm. Based on the results of our robot simulation, we determined a safe turning clearance distance with a six-body diameter between the robot and the obstacles. When the clearance is less than this value, additional methods such as backward locomotion may need to be applied for paths with high obstacle offset. Furthermore, for a worm-like robot, the paths of subsequent segments will be slightly different than the path of the head segment. Here, we show that as the number of segments increases, the differences between the head path and tail path increase, necessitating greater lateral clearance margins.

Evaluation of locomotion methods in virtual reality navigation environments: An involuntary position shift and task performance

• Effects of four locomotion methods on user safety and performance were examined • Walking in place and running in place can cause involuntary movements of the user • For each locomotion method, larger involuntary movements were found in the turning course than in the straight course • Teleportation required the shortest task completion time, but the error time ratio was the largest • The safety issue of the users’ involuntary movement should be solved Navigation is a representative task in a virtual environment (VE). The locomotion methods affect the navigation performance and can cause involuntary movements by the users, which may cause critical safety problems. Thus, this study examined the effects of different locomotion methods on the users’ involuntary position shift (IPS) and navigation performance in a VE. Twenty-one healthy participants performed the navigation task with four locomotion methods: walking in place (WIP), running in place (RIP), joystick, and teleportation. The results showed that a larger amount of IPS occurred with VE navigation under WIP and RIP conditions than joystick and teleportation conditions, which may cause critical safety problems, such as collisions with walls. Moreover, teleportation took the shortest task completion time, but its error time ratio was the largest. These results are expected to help develop basic guidelines for applying locomotion methods to specific situations and establishing safety precautions for virtual reality experiences.

A Comparative Study of Virtual Reality Methods of Interaction and Locomotion Based on Presence, Cybersickness, and Usability

In recent years, virtual reality has experienced notorious technological advances in a quite short time. In an attempt to quickly response to this technical developments, some designs and developments of inmersive environments have caused different symptoms such as dizziness or disorientation. This work aims to analyze different methods of interaction and locomotion used in inmersive environments (Point of Interest, Gamepad, Teleport, and Room-Scale) in three different aspects: presence, cybersickness, and usability. We have designed and developed an experimental environment to carry out an empirical analysis with 48 subjects comparing the results obtained in different perceptual experiments. As a result, we provide a guideline for the use of these methods of interaction and locomotion in virtual reality.

Using virtual reality treadmill as a locomotion technique in a navigation task: Impact on user experience – case of the KatWalk

This paper reports empirical results from a study on the impact of the KatWalk virtual reality omnidirectional treadmill on the user experience. The omnidirectional treadmill is a mechanical device, that allows the user to perform locomotive motion in any direction, allowing for 360 degrees of horizontal movement. This locomotion method appeared as a potential solution of the locomotion problem in virtual reality after the emergence and the democratization of the new generation of head-mounted display systems such as HTC Vive and Oculus Rit. However, little empirical work has been done to test the efficiency of the tool as a locomotion technique in virtual environments. Twenty-four subjects (13 females, mean age = 30.38, SD = 6.32) participated in the experiment. Results showed that the tool is suitable for traveling in virtual environments seen through head-mounted display systems, whether they are composed of plan or bumpy ground, with or without obstacles.

Terrain classification and adaptive locomotion for a hexapod robot Qingzhui

Legged robots have potential advantages in mobility compared with wheeled robots in outdoor environments. The knowledge of various ground properties and adaptive locomotion based on different surface materials plays an important role in improving the stability of legged robots. A terrain classification and adaptive locomotion method for a hexapod robot named Qingzhui is proposed in this paper. First, a force-based terrain classification method is suggested. Ground contact force is calculated by collecting joint torques and inertial measurement unit information. Ground substrates are classified with the feature vector extracted from the collected data using the support vector machine algorithm. Then, an adaptive locomotion on different ground properties is proposed. The dynamic alternating tripod trotting gait is developed to control the robot, and the parameters of active compliance control change with the terrain. Finally, the method is integrated on a hexapod robot and tested by real experiments. Our method is shown effective for the hexapod robot to walk on concrete, wood, grass, and foam. The strategies and experimental results can be a valuable reference for other legged robots applied in outdoor environments.

Design and conception of Arduino based quadruped robot

In their world, mobile robots can travel about and are not fixed to one physical position. Mobile robots may be “autonomous” (AMR, autonomous mobile robots), meaning they can handle an unregulated setting. Nowadays, mobile robots are becoming useful in many departments such as warehouses, hospitals, industries, military and security purposes. This robot mainly uses legged type (human-like legs or animal-like legs), wheeled type, and tracks follower type. Legged robots are mobile robots that use mechanical limbs for motion, similar to wheeled robots, but compared to their wheeled counterparts, their locomotion methods are more complex, performing much better on rough terrain than wheeled robots. With the incorporation of sensors such as DH11 (Temperature sensor), MQ2 (Smoke sensor), HC-SR04 (Ultrasonic sensor), the four-legged spider robot can monitor the environment, and the OLED display gives the respective readings. This design will enhance and improve the existing development of spider robots.

Robust Footstep Planning and LQR Control for Dynamic Quadrupedal Locomotion

In this paper, we aim to improve the robustness of dynamic quadrupedal locomotion through two aspects: 1) fast model predictive foothold planning, and 2) applying LQR to projected inverse dynamic control for robust motion tracking. In our proposed planning and control framework, foothold plans are updated at 400 Hz considering the current robot state and an LQR controller generates optimal feedback gains for motion tracking. The LQR optimal gain matrix with non-zero off-diagonal elements leverages the coupling of dynamics to compensate for system underactuation. Meanwhile, the projected inverse dynamic control complements the LQR to satisfy inequality constraints. In addition to these contributions, we show robustness of our control framework to unmodeled adaptive feet. Experiments on the quadruped ANYmal demonstrate the effectiveness of the proposed method for robust dynamic locomotion given external disturbances and environmental uncertainties.

Multi-Technique Redirected Walking Method

The Room-Scale locomotion method is one of the most realistic locomotion methods used in virtual reality technologies. This is due to the natural interaction obtained through the tracking of its controllers and the head-mounted display with six degrees of freedom. However, its mapping by position between the physical and the virtual world limits the user's movement to the physical workspace provided by the corresponding device. Redirected Walking methods use gain algorithms that add modifications to the virtual movement of the user, optimizing the virtual workspace in the same physical workspace. In this paper, we develop a new Redirected Walking method, which combines the modification of three gain algorithms (curvature gain, rotation gain, and translation gain), a new algorithm (deviation gain), a path predictive method of the user's locomotion, a proportional distance to the center function, and a user direction smoothing function that softens the effect of the algorithms. Complementing the new method, we offer an automatic calibration system that allows the user to use our method in a personalized way.

Path-Integral-Based Reinforcement Learning Algorithm for Goal-Directed Locomotion of Snake-Shaped Robot

This paper proposes a goal-directed locomotion method for a snake-shaped robot in 3D complex environment based on path-integral reinforcement learning. This method uses a model-free online Q-learning algorithm to evaluate action strategies and optimize decision-making through repeated “exploration-learning-utilization” processes to complete snake-shaped robot goal-directed locomotion in 3D complex environment. The proper locomotion control parameters such as joint angles and screw-drive velocities can be learned by path-integral reinforcement learning, and the learned parameters were successfully transferred to the snake-shaped robot. Simulation results show that the planned path can avoid all obstacles and reach the destination smoothly and swiftly.

Design and Fabrication of Octopod for Survey and Rescue Operation

Although wheel is an ideal method of locomotion and the invention of the spoke wheel made a wheel lighter and swifter, a wheel cannot function well on slanted or rough surfaces. Further, the load support of the wheel is limited to a point of the whole wheel in contact with the ground. In rough and rocky terrains, wheels become ineffective or not able to serve the purpose. On realizing this fact, a new design and fabrication is suggested and a walking robot is designed accordingly. In the practical life, the usage of robots has been felt especially in search and rescue operations, extraterrestrial exploration and many more such applications. In these areas, the existing wheeled robots are not able to perform well and hence they can be replaced with walking robots of special design. In distant areas, many expeditions of walking robot need the tele-operation mode. Yet, sensing the terrains and controlling the robots become difficult for a human operator with the available capabilities and hence the walking robot should be designed in such a way that even with limited feedback from the remote operator, it should have adequate autonomy to take due advantage of its competency and capabilities. The paper envisages a new method of real-time motion planning on rough and rugged surface and in this paper, an octopod is designed, developed and fabricated accordingly.

Recent Trends of the In-Pipe Inspection Robotic System from Academia and Industry Perspectives

This paper presents the recent designs of the in-pipe inspection robotic system from the researchers in the academia and industrial fields. The scope of the paper will focus on the designs, locomotion of the systems and the actuator that will actuate or provide force to drive the in-pipe robot forward. The study covers the trends of the research from recent years to date. It is observable that most of the researches conducted by academic researchers focused on the designs and locomotion of the robots which commonly used wheel drive, screw drive and modular locomotion method. The screw drive in-pipe robotic system has a set of wheels located at certain distance apart from the centre of the body with a certain angle so that the system rotates like a screw when it is actuated. On the contrary, the in-pipe robotic system from the industry like oil and gas industry uses wheel type robot combined with other parts like disc, cups, scraper and attached with the sensory system to conduct the inspection.

Locomotion methods of microrobots and targeted drug delivery

Locomotion methods of microrobots and targeted drug delivery