Bio-inspired Jumping Robot Research Articles

Port-Hamiltonian modeling and jumping trajectory tracking control for a bio-inspired quadruped robot

Applying jumping locomotion into autonomous mobile robot is an effective way for improving abilities to overcome barriers and pass through complex terrains. In this paper, based on the designed structural framework for bio-inspired quadruped jumping robot, dynamic model is established by utilizing port-Hamiltonian with dissipation (pHd) method, and a passivity-based control strategy for the robot joints trajectory tracking is presented. First, morphology and biomimetics knowledges of frogs (a kind of animals with excellent jumping skill) motivate us to complete a bio-inspired jumping robot framework based on frog’s motion mechanism and body structure with torsional springs as energy storage device. Then, combining system passivity and dissipation, port-Hamiltonian method is utilized to build a dynamic model for expressing the relationship of energy and force in the designed robot. Jumping process analysis of different stages is also designed for ensuring the robot to complete taking-off and landing stages successfully. Next, with the definition of extending feasible robotic joint trajectory by La Salle invariant set principle, interconnection and damping assignment passivity-based control (IDA-PBC) method is exerted to obtain a trajectory controller for realizing smoothly and stably trajectory tracking in joint space. At last, simulation results show the reasonableness of the designed framework. By comparing our method with state-feedback and sliding mode control, effectiveness of the dynamic model and trajectory controller is also verified.

Directional takeoff, aerial righting, and adhesion landing of semiaquatic springtails

Springtails (Collembola) have been traditionally portrayed as explosive jumpers with incipient directional takeoff and uncontrolled landing. However, for these collembolans that live near the water, such skills are crucial for evading a host of voracious aquatic and terrestrial predators. We discover that semiaquatic springtails, Isotomurus retardatus, can perform directional jumps, rapid aerial righting, and near-perfect landing on the water surface. They achieve these locomotive controls by adjusting their body attitude and impulse during takeoff, deforming their body in midair, and exploiting the hydrophilicity of their ventral tube, known as the collophore. Experiments and mathematical modeling indicate that directional-impulse control during takeoff is driven by the collophore's adhesion force, the body angle, and the stroke duration produced by their jumping organ, the furcula. In midair, springtails curve their bodies to form a U-shape pose, which leverages aerodynamic forces to right themselves in less than ~20 ms, the fastest ever measured in animals. A stable equilibrium is facilitated by the water adhered to the collophore. Aerial righting was confirmed by placing springtails in a vertical wind tunnel and through physical models. Due to these aerial responses, springtails land on their ventral side ~85% of the time while anchoring via the collophore on the water surface to avoid bouncing. We validated the springtail biophysical principles in a bioinspired jumping robot that reduces in-flight rotation and lands upright ~75% of the time. Thus, contrary to common belief, these wingless hexapods can jump, skydive, and land with outstanding control that can be fundamental for survival.

Rigid-flexible coupling dynamic modeling and performance analysis of a bioinspired jumping robot with a six-bar leg mechanism

Rigid-flexible coupling dynamic modeling and performance analysis of a bioinspired jumping robot with a six-bar leg mechanism

Dynamic stability of bio-inspired biped robots for lateral jumping in rugged terrain

Bio-inspired jumping robots should achieve stable jumping in field environment. Robots easily lose stability because of the complex terrain and large speed change. Lateral jumping of the robot with four-bar jumping legs under rugged terrain was used as the research object, and a method to achieve good dynamic stability by adjusting the leg attitudes of the robot was proposed. The stability criteria were proposed hierarchically on the basis of the analysis of the jumping mechanism of creatures. Then, the dynamic model of the robot jumping on the slope was established, and the effect of different parameters on dynamic stability was analyzed to carry out the primary selection of parameters. Then, the method of maintaining dynamic stability was proposed. On the basis of ensuring large motion distances and stable driving torques, leg attitudes were considered the optimization parameters. Thus, the robot does not overturn or turn over uncontrollably in the take-off, buffering, and flight phases. Analysis results of robot jumping in plane and 3D space under different terrains prove the feasibility of this method. In particular, the dynamic stability of the robot is better if the take-off direction is considered an optimization parameter. The simulation results also proved the accuracy of the analysis results. The research results provide a theoretical basis to realize stable continuous jumping of bio-inspired biped robots.

Design and Demonstration of a Flying-Squirrel-Inspired Jumping Robot with Two Modes

The jumping–gliding robot is a kind of locomotion platform with the capabilities to jump on the ground and glide through the air. The jumping of this robot has to juggle the requirements of initial velocity and posture for entry to gliding and progressing on the ground. Inspired by flying squirrels, we proposed the concept of flexible wing-limb blending platform and designed a robot with two jumping modes. The robot can takeoff with different speeds and stances, and adjust aerial posture using the swing of forelimbs. To the best of our knowledge, this is the first miniature and bio-inspired jumping robot that can autonomically change the speeds and stances when takeoff. Experimental results show that the robot can takeoff at about 3 m/s and pitch angle of 0° in the mode of jumping for gliding and adjust the pitch angle at the top to 0°~10° by actuating the forelimbs swing according to the requirement of gliding. In the mode of jumping for progress, the robot can takeoff at about 2 m/s with a pitch angle of 20° and then intermittently jump with a distance of 0.37 m of once jump and an average progress speed of 0.2 m/s. The robot presented in this paper lays the foundation for the development of flexible wing-limb blending platform, which is capable of jumping and gliding.

Modeling, comparison and evaluation of one-DOF six-bar bioinspired jumping leg mechanisms

One degree-of-freedom (DOF) jumping leg has the advantages of simple control and high stiffness, and it has been widely used in bioinspired jumping robots. Compared with four-bar jumping leg, six-bar jumping leg mechanism can make the robot achieve more abundant motion rules. However, the differences among different configurations have not been analyzed, and the choice of configurations lacks basis. In this study, five Watt-type six-bar jumping leg mechanisms were selected as research objects according to the different selection of equivalent tibia, femur and trunk link, and a method for determining the dimension of the jumping leg was proposed based on the movement law of jumping leg of locust in take-off phase. On this basis, kinematics indices (sensitivity of take-off direction angle and trunk attitude angle), dynamics indices (velocity loss, acceleration fluctuation, and mean and variance of total inertial moment) and structure index (distribution of center of mass) were established, and the differences of different configurations were compared and analyzed in detail. Finally, according to the principal component analysis method, the optimal selection method for different configurations was proposed. This study provides a reference for the design of one DOF bioinspired mechanism.

Jumping Locomotion Strategies: From Animals to Bioinspired Robots

Jumping is a locomotion strategy widely evolved in both invertebrates and vertebrates. In addition to terrestrial animals, several aquatic animals are also able to jump in their specific environments. In this paper, the state of the art of jumping robots has been systematically analyzed, based on their biological model, including invertebrates (e.g., jumping spiders, locusts, fleas, crickets, cockroaches, froghoppers and leafhoppers), vertebrates (e.g., frogs, galagoes, kangaroos, humans, dogs), as well as aquatic animals (e.g., both invertebrates and vertebrates, such as crabs, water-striders, and dolphins). The strategies adopted by animals and robots to control the jump (e.g., take-off angle, take-off direction, take-off velocity and take-off stability), aerial righting, land buffering, and resetting are concluded and compared. Based on this, the developmental trends of bioinspired jumping robots are predicted.

Impact of Different Developmental Instars on Locusta migratoria Jumping Performance.

Ontogenetic locomotion research focuses on the evolution of locomotion behavior in different developmental stages of a species. Unlike vertebrates, ontogenetic locomotion in invertebrates is poorly investigated. Locusts represent an outstanding biological model to study this issue. They are hemimetabolous insects and have similar aspects and behaviors in different instars. This research is aimed at studying the jumping performance of Locusta migratoria over different developmental instars. Jumps of third instar, fourth instar, and adult L. migratoria were recorded through a high-speed camera. Data were analyzed to develop a simplified biomechanical model of the insect: the elastic joint of locust hind legs was simplified as a torsional spring located at the femur-tibiae joint as a semilunar process and based on an energetic approach involving both locomotion and geometrical data. A simplified mathematical model evaluated the performances of each tested jump. Results showed that longer hind leg length, higher elastic parameter, and longer takeoff time synergistically contribute to a greater velocity and energy storing/releasing in adult locusts, if compared to young instars; at the same time, they compensate possible decreases of the acceleration due to the mass increase. This finding also gives insights for advanced bioinspired jumping robot design.

Time-scale mechanical behaviors of locust semi-lunar process cuticles under power amplification for rapid movements

The semi-lunar process (SLP) is a key component in the power amplification of locusts to achieve rapid movements. Its mechanical properties determine the amount of the power amplification and the subsequent locomotion performance. As previously reported, the SLP cuticle endures physiological dynamic loadings. However, the time-scale mechanical properties of the SLP are still unknown, especially under stress relaxation and cyclic loadings. In this paper, the SLP cuticles of adult desert locusts (Schistocerca gregaria) were studied using stress relaxation and cyclic tests, with loadings corresponding to the physiological loading conditions of the power amplification. The SLP cuticle was found to show pronounced stress relaxation behavior with the resultant force and an evident time shift between the maximal displacement and the maximal resultant force. The number of loading cycles before mechanical failure (life cycle number) increases when the SLP cuticle is cyclically loaded by a lower stress level. Moreover, the failure strength of the SLP at low cycles equals the physiological stress level in the power amplification, implying that the healing of the cuticle might contribute to the successful performance of numerous jumps in the course of the adult locust life. This study not only deepens our understanding of the power amplification mechanism of locust locomotion but also provides valuable knowledge for the design optimization of bioinspired jumping robots and elastic energy storage devices.

Design, Optimization, and Experiment on a Bioinspired Jumping Robot with a Six-Bar Leg Mechanism Based on Jumping Stability

A jumping leg with one degree of freedom (DOF) is characterized by high rigidity and simple control. However, robots are prone to motion failure because they might tip over during the jumping process due to reduced mechanism flexibility. Mechanism design, configuration optimization, and experimentation were conducted in this study to achieve jumping stability for a bioinspired robot. With locusts as the imitated object, a one-DOF jumping leg mechanism was designed taking Stephenson-type six-bar mechanism as reference, and kinematic and dynamic models were established. The rotation angle of the trunk and the total inertia moment were used as stability criteria, and the sensitivity of different links to the target was analyzed in detail. With high-sensitivity link lengths as the optimization parameters, a configuration optimization method based on the particle swarm optimization algorithm was proposed in consideration of the different constraint conditions of the jumping leg mechanism. Optimization results show that this method can considerably improve optimization efficiency. A prototype of the robot was developed, and the experiment showed that the optimized trunk rotation angle and total inertia moment were within a small range and can thus meet the requirements of jumping stability. This work provides a reference for the design of jumping and legged robots.

Biologically inspired jumping robots: A comprehensive review

Applying concepts and methods of bionics to endow autonomous robots with elegant and agile mobility just like natural living beings is gradually becoming a hot research topic in intelligent robot field. Compared with walking, crawling, rolling and other motion modes, jumping performs considerable advantages that can leap across obstacles and move to different heights in agility and flexibility. In this paper, we specifically review the developments of biologically inspired jumping robots in the past decades, and give comprehensive analysis on some key technologies for implementing a practical jumping robot effectively. First, the jumping mechanism of frog (amphibian, quadruped), locust (arthropod, hexapod), kangaroo (mammality, bipedalism) as examples of typical animals good at jumping is introduced and analyzed, from which it is concluded that power sources, limbs coordination and control are key elements for excellent jumping performances, which should be synthetically improved by combination with structure design and model establishment. Then, spring loaded inverted pendulum (SLIP), bio-inspired open-chain and closed-chain multi-linkage as representative jumping mechanical structures, their characteristics are explored accompanied with dynamic analysis. After a detailed analysis to actuators and energy storage devices and a comprehensive summarization to functional and soft materials commonly applied in jumping robots, different control methods and strategies adopted to achieve better jumping performance are reviewed and analyzed, from self-righting, driving control to path planning. Especially, how to analyze the stability of a jumping control system and how to stabilize it are explained theoretically by taking a vertical monopedal jumping robot as an example and via limit cycle analysis. Finally, some feasible and potential future developments in bio-inspired jumping robots are also presented after detailed discussions on current status and existing deficiencies.

Dynamic model and performance analysis of rigid-flexible coupling four-bar leg mechanism for small scale bio-inspired jumping robot

Bio-inspired jumping robot can imitate the jumping process of creatures, and can move in environment with large obstacles. This type of robot can be applied to complex situations such as earthquakes and landslides, and has a broad application prospect. Aiming at the problems of the existing micro bionic jumping robots, such as the simple dynamic model and the unclear rigid-flexible coupling characteristics, the dynamic modeling and performance analysis of rigid-flexible coupling jumping leg is conducted in this paper. Based on the analysis of the jumping mechanism of stick insect, a design method of four-bar jumping leg mechanism under multiple constraint conditions is put forward. Then the dynamic model of the rigid-flexible coupling four-bar jumping leg with flexible equivalent tibia and elastic joint is established combining with Lagrange and Newton–Euler dynamic modeling methods, which can describe the dynamic characteristics of the robot quantitatively during jumping. The relationship between the stiffness of flexible tibia and jumping performance is analyzed, which includes energy storage capacity, take-off velocity/acceleration and jumping stability. The analysis results show that proper reduction of stiffness of flexible tibia can improve the dynamic performance of small scale bio-inspired jumping robot. This study offers primary theories for design and analysis of rigid-flexible coupling four-bar jumping leg with flexible equivalent tibia and elastic joint, and it establishes a theoretical basis for studies and engineering applications.

A Survey of Bioinspired Jumping Robot: Takeoff, Air Posture Adjustment, and Landing Buffer.

A bioinspired jumping robot has a strong ability to overcome obstacles. It can be applied to the occasion with complex and changeable environment, such as detection of planet surface, postdisaster relief, and military reconnaissance. So the bioinspired jumping robot has broad application prospect. The jumping process of the robot can be divided into three stages: takeoff, air posture adjustment, and landing buffer. The motivation of this review is to investigate the research results of the most published bioinspired jumping robots for these three stages. Then, the movement performance of the bioinspired jumping robots is analyzed and compared quantitatively. Then, the limitation of the research on bioinspired jumping robots is discussed, such as the research on the mechanism of biological motion is not thorough enough, the research method about structural design, material applications, and control are still traditional, and energy utilization is low, which make the robots far from practical applications. Finally, the development trend is summarized. This review provides a reference for further research of bioinspired jumping robots.

Mechanism of Locust Air Posture Adjustment

Stimulated locusts often tumble during the jumping process. Locusts can also recover their bodies in the air for flight or landing stability. To increase jumping distance and avoid landing collision of bio-inspired jumping robots, the mechanism of air posture adjustment of locusts is examined in this research. This mechanism can be used to improve the stability of robot. The abdomen swings, wing motions, and the variations in body angle are recorded by a high-speed camera when locusts free fall in air with normal or upside-down initial posture. Results indicate that the wings and abdomen are mainly utilized for air posture adjustment. Moreover, abdomen swing and forewing rotation have positive effects on body pitch. However, locusts have difficulty in recovering their bodies from the upside-down posture without wings, although the body pitch caused by unpredictable perturbation in air can be compensated through abdomen swing. Consequently, body roll is attributed to the wing motion, which is related to two factors, namely, the different flapping amplitudes of the wings on both sides, and the different flapping velocities of wings during the upstroke and downstroke periods. This research may provide reference for the design of jumping robots.

Structural-Parameter-Based Jumping-Height-and-Distance Adjustment and Obstacle Sensing of a Bio-Inspired Jumping Robot

Jumping-height-and-distance (JHD) active adjustment capability is important for jumping robots to overcome different sizes of obstacle. This paper proposes a new structural-parameter-based JHD active adjustment approach for our previous jumping robot. First, the JHD adjustments, modifying the lengths of different legs of the robot, are modelled and simulated. Then, three mechanisms for leg-length adjustment are proposed and compared, and the screw-and-nut mechanism is selected. And for adjusting of different structural-parameters using this mechanism, the one with the best JHD adjusting performance and the lowest mechanical complexity is adopted. Thirdly, an obstacle-distance-and-height (ODH) detection method using only one infrared sensor is designed. Finally, the performances of the proposed methods are tested. Experimental results show that the jumping-height-and-distance adjustable ranges are 0.11 m and 0.96 m, respectively, which validates the effectiveness of the proposed JHD adjustment method.

Research on one Bio-inspired Jumping Locomotion Robot for Search and Rescue

Jumping locomotion is much more effective than other locomotion means in order to tackle the unstructured and complex environment in research and rescue. Here, a bio-inspired jumping robot with a closed-chain mechanism is proposed to achieve the power amplification during taking-off. Through actuating one variable transmission mechanism to change the transmission ratio, the jumping robot reveals biological characteristics in the phase of posture adjustment when adjusting the height and distance of one jump. The kinematics and dynamics of the simplified jumping mechanism model in one jumping cycle sequence are analysed. A compliant contact model considering nonlinear damping is investigated for jumping performance under different terrain characteristics. The numerical simulation algorithm with regard to solving the dynamical equation is described and simulation results are discussed. Finally, one primary prototype and experiment are described. The experimental results show the distance of jumping in the horizontal direction increases with the increasing gear ratio, while the height of jumping decreases in reverse. The jumping robot can enhance the capability to adapt to unknown cluttered environments, such as those encountered in research and rescue, using this strategy.

A bio-inspired jumping robot: Modeling, simulation, design, and experimental results

This paper presents the design of a jumping robot inspired by jumping locomotion of locusts. The mechanisms of jumping, self-righting, steering, and takeoff angle adjusting are modeled and simulated firstly. Then the 3D model of the robot is designed and a prototype of the robot is fabricated. An eccentric cam with quick return characteristics is used by the jumping mechanism to compress torsion springs for energy storing and to trigger the springs for a quick release of energy. The self-righting, steering, and takeoff angle adjusting capabilities of the robot are achieved by adding a rotatable pole leg. The pole leg can prop up the body of the robot when it falls down. The pole leg can also steer the robot to turn step by step. By adjusting its center of mass (COM) using the pole leg with an additional weight, the robot can jump at different takeoff angles. A 9cm×7cm×12cm, 154g jumping robot prototype is implemented. The fundamental characteristics of the robot are tested. Experimental results show that the constructed robot can jump more than 88cm high at a takeoff angle of 80.33°. The robot rotates about 277° in the air during jumping. The robot can self-right when it falls down to its left, right, and front sides in 9s, 9s, and 26s respectively. The robot can steer 360° in 42s with 14 steps, about 25.7° per step. Its takeoff angle ranges between 80.33° and 86.92°. The robot can continuously jump to overcome stairs and jump forward in outdoor environments with self-righting and steering. The experimental results are compared with the simulation results. The differences between them are explained.

Design and Implementation of a Remote Control System for a Bio-Inspired Jumping Robot

This paper presents the design and implementation of a remote control system for a bio-inspired jumping robot. The system is composed of a server, a gateway, and a jumping robot. The proposed remote control system is used to monitor the posture of the jumping robot and control it in remote places. A three-axis accelerometer is used to detect the tilts of the robot. A compass is used to sense the azimuth of the robot. The calibrations of the accelerometer and the compass are conducted. The sensor data of the robot can be sent to the server through a ZigBee wireless sensor network (WSN). An algorithm is designed to calculate the posture of the robot from the sensor data. The posture of the robot can be displayed on the human-computer interface of the server using the virtual reality technology of OpenGL. The robots can be controlled by the operator through the interface. Two experiments have been done to verify the posture detection method and test the performance of the system.

Research on the bio-inspired micro jumping robot

This paper presents a review over bio-inspired concept of jumping robot for locomotion on uneven terrains.First,scale effect is proved by comparison of different speeds of animals and Froude number is introduced to demonstrate the higher effectiveness of jumping mode:in the small robots.The worldwide development of design and application of jumping robots in Japan,USA.Italy,etc,is introduced.Also,description over key techniques used in the robot is given about locomotion,energy storing and releasing,stabilization,sensor integration and obstacle detection.The prospect of the application area is discussed in the end. Key words: Jumping robot; Bionic; Movement mechanism; Intdhet control