Vertical Movement of Resonance Hopping Robot with Electric Drive and Simple Control System

In the paper vertical movements of resonance hopping robot with one leg and electric drive are considered. Special construction of hopping robot with compensation of losses during flight of the robot allows to employ a relatively simple control system as well as to get a stable regime of its operation. The designed robot has self-properties to maintain a specified height of jumping even with simple control system. Results of dynamical calculations, simulations and experimental testing are presented.In the paper vertical movements of resonance hopping robot with one leg and electric drive are considered. Special construction of hopping robot with compensation of losses during flight of the robot allows to employ a relatively simple control system as well as to get a stable regime of its operation. The designed robot has self-properties to maintain a specified height of jumping even with simple control system. Results of dynamical calculations, simulations and experimental testing are presented

Back Flips with a Hexapedal Robot

We report on the design and analysis of a controller which can achieve dynamical self-righting of our hexapedal robot, RHex. We present an empirically developed control procedure which works reasonably well on indoor surfaces, using a hybrid energy pumping strategy to overcome torque limitations of its actuators. Subsequent modeling and analysis yields a new controller with a much wider domain of success as well as a preliminary understanding of the necessary hybrid control strategy. Simulation results demonstrate the superiority of the improved control strategy to the first generation empirically designed controller

Stereo Omnidirectional Vision for a Hopping Robot

Abstract-This paper proposes a new geometrical structure for stereoscopic vision using omnidirectional cameras. The motivation of this work comes from the desire to equip a small hopping robot with an efficient and robust vision system to perform self localization during exploration missions. Because of size and weight constraints, we selected the Panoramic Annular Lens, for which no geometric model of stereo configuration was available. The paper describes the geometrical optical properties of the single lens and proposes a configuration for doing stereo vision with this lens. The analitical properties as well as the requirements of the complete system are discussed in the paper

Dual Drive for Vertical Movement of Resonance Hopping Robot

In the present study vertical movements of resonance hopping robot of special construction with one leg and dual drive are considered. The construction of hopping robot with compensation of losses during flight of the robot allows employing a simple control system and having a stable regime of its operation so that the robot has self-property to maintain a specified height of jumping. The data on dynamical calculation, simulations and experimental testing are discussed. The solution of the problem of actuator’s optimum parameters choice (including variable transmission ratio) for the considered robot is presented.В настоящей работе рассматриваются вертикальные движения резонансного прыгающего робота специальной конструкции с одной ногой и приводом с изменяемыми свойствами. Конструкция робота предусматривает, что компенсация потерь энергии производится в фазе полета. Это дает возможность использовать простую систему управления и позволяет стабилизировать рабочий режим за счет того, что робот имеет естественную самостабилизацию заданной высоты прыжков. Обсуждаются результаты расчетов, моделирования и экспериментов. Для рассматриваемого робота представлено решение задачи выбора оптимальных параметров, включая параметры привода с изменяемыми свойствами

A Dynamics and Stability Framework for Avian Jumping Take-off

Jumping take-off in birds is an explosive behaviour with the goal of providing a rapid transition from ground to airborne locomotion. An effective jump is predicated on the need to maintain dynamic stability through the acceleration phase. The present study concerns understanding how birds retain control of body attitude and trajectory during take-off. Cursory observation suggests that stability is achieved with relatively little cost. However, analysis of the problem shows that the stability margins during jumping are actually very small and that stability considerations play a significant role in selection of appropriate jumping kinematics. We use theoretical models to understand stability in prehensile take-off (from a perch) and also in non-prehensile take-off (from the ground). The primary instability is tipping, defined as rotation of the centre of gravity about the ground contact point. Tipping occurs when the centre of pressure falls outside the functional foot. A contribution of the paper is the development of graphical tipping stability margins for both centre of gravity location and acceleration angle. We show that the nose-up angular acceleration extends stability bounds forward and is hence helpful in achieving shallow take-offs. The stability margins are used to interrogate simulated take-offs of real birds using published experimental kinematic data from a guinea fowl (ground take-off) and a diamond dove (perch take-off). For the guinea fowl the initial part of the jump is stable, however simulations exhibit a stuttering instability not observed experimentally that is probably due to absence of compliance in the idealised joints. The diamond dove model confirms that the foot provides an active torque reaction during take-off, extending the range of stable jump angles by around 45{\deg}.Comment: 21 pages, 11 figures; supplementary material: https://figshare.com/s/86b12868d64828db0d5d; DOI: 10.6084/m9.figshare.721056

Simulation of the Landing Buffer of a Three-Legged Jumping Robot

In recent years, the research of planetary exploration robots has become an active field. The jumping robot has become a hot spot in this field. This paper presents a work modelling and simulating a three-legged jumping robot, which has a powerful force, high leaping performance, and good flexibility. In particular, the jumping of the robot was simulated and the landing buffer of the robot was analyzed. Because this jumping robot lacks landing buffer, this paper verifies a method of absorbing landing kinetic energy to improve landing stability and storing it as the energy for the next jump in the simulation. Through the landing simulation, the factors affecting the landing energy absorption are identified. Moreover, the simulation experiment verifies that the application of the intermediate axis theorem helps to absorb more energy and adjust the landing attitude of the robot. The simulation results in this paper can be applied to the optimal design of robot prototypes and provide a theoretical basis for subsequent research

A minimally actuated hopping rover for exploration of celestial bodies

Abstract: This paper describes a minimalist hopping robot that can perform basic exploration tasks on Mars or other moderate gravity bodies. We show that a single actuator can control the vehicle’s jumping and steering operations, as well as the panning of an on-board camera. Our novel thrusting linkage also leads to good system efficiency. The inherent minimalism of our hopping paradigm offers interesting advantages over wheeled and legged mobility concepts for some types of planetary exploration. The paper summarizes the evolutionary development of the system, issues relevant to the design of such jumping systems, and experimental results obtained with system prototypes.

A Biologically Inspired Jumping and Rolling Robot

Mobile robots for rough terrain are of interest to researchers as their range of possible uses is large, including exploration activities for inhospitable areas on Earth and on other planets and bodies in the solar system, searching in disaster sites for survivors, and performing surveillance for military applications. Nature generally achieves land movement by walking using legs, but additional modes such as climbing, jumping and rolling are all produced from legs as well. Robotics tends not to use this integrated approach and adds additional mechanisms to achieve additional movements. The spherical device described within this thesis, called Jollbot, integrated a rolling motion for faster movement over smoother terrain, with a jumping movement for rougher environments. Jollbot was developed over three prototypes. The first achieved pause-and-leap style jumps by slowly storing strain energy within the metal elements of a spherical structure using an internal mechanism to deform the sphere. A jump was produced when this stored energy was rapidly released. The second prototype achieved greater jump heights using a similar structure, and added direction control to each jump by moving its centre of gravity around the polar axis of the sphere. The final prototype successfully combined rolling (at a speed of 0.7 m/s, up 4° slopes, and over 44 mm obstacles) and jumping (0.5 m cleared height), both with direction control, using a 0.6 m spherical spring steel structure. Rolling was achieved by moving the centre of gravity outside of the sphere’s contact area with the ground. Jumping was achieved by deflecting the sphere in a similar method to the first and second prototypes, but through a larger percentage deflection. An evaluation of existing rough terrain robots is made possible through the development of a five-step scoring system that produces a single numerical performance score. The system is used to evaluate the performance of Jollbot.EThOS - Electronic Theses Online ServiceGBUnited Kingdo