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By An amphibious bionic robot has good movement ability under several working conditions, so as to better perform tasks in complex terrain environments. In this study, the development background, research status and main applications of amphibious bionic robots are summarized. According to the degree of bionic reference, amphibious bionic robots are divided into two categories: imitating motion mode and imitating motion structure. The relevant research is introduced and the characteristics of different robot types are analyzed. Furthermore, the technical advantages and typical application scenarios of amphibious bionic robots are described.

Experimental research is conducted followed by a comparative analysis of the results, which are obtained in the process of theoretical and experimental studies, to check the theoretical research adequacy of the roller forming unit with the crank drive. We have developed the experimental research program for the roller forming unit with the crank drive. The research stand of roller forming with the crank drive was used for experimental studies. This research stand allows you to carry out full-value experimental studies on the determination of dynamic loads unrestricted. The experimental research program provides the determination of the interaction force for the compaction roller with the construction mixture, the force in the unit connecting rod, the torque on the unit drive shaft and the power, which is necessary for the realization of the forming process. The determination of these loads will make it possible to realistically assess the condition of the forming unit and rationally carry out its design and operation. Plan, procedure and processing of experimental research data have been developed. The measuring and recording equipment were selected to determine the force loads of the research stand for conducting experimental studies, which transforms the received numerical data into Microsoft Excel for their processing. The measurement of the force in the connecting rod and the interaction vertical force of the compaction roller with the construction mixture was carried out using strain gauges. These are pasted according to the bridge scheme on the connecting rod and the metal plate, which is located in the form with the building mixture under the compaction roller. RK 435 universal clamps, which make it possible to measure the line voltage, the current strength and the power under unit different load modes, are used to measure the power required for the forming process.

The combined dynamic mode of the reciprocating motion for a forming trolley is calculated to increase the reliability and durability of the roller forming unit. The criterion action is used as a criterion of the motion mode, which is an integral over time with the sub-integral function that expresses the acceleration «energy» when calculating the combined dynamic motion mode of the forming trolley in the acceleration and braking areas. The change functions of the kinematic characteristics of the forming trolley during its motion from one extreme position to another, which correspond to the combined dynamic mode of the reciprocating motion, are calculated. The displacement and speed of the forming trolley in the acceleration and braking areas change smoothly with this motion mode, without creating significant dynamic loads in the unit, which in turn has a positive effect on its durability. The variation law of the compaction rollers angular velocity is calculated by taking into account the change functions of the forming trolley speed. The roller forming unit design with a drive from the high-torque stepper motor is proposed, which is mounted in the compaction rollers of the forming trolley and provides the combined dynamic mode of reciprocating motion for the forming trolley. The surface quality of the processed concrete mixture is increased, dynamic loads in the drive mechanism elements are reduced, unnecessary destructive loads on the frame construction are disappeared and, accordingly, the reliability and durability of the unit as a whole are increased, when we use the such drive in the unit.

As an important part of large passenger aircraft, the analysis of motion state and motion mode of passenger doors is very important for the design of door function and motion mechanism. From the viewpoint of topological synthesis of robot mechanism, it is proposed for the first time to abstract the opening motion mechanism of a certain type of the sideward opening aircraft door into a parallel mechanism composed of two SS branches and one ◇(R//R//R//R)⊥R//R branch, and research on the overall motion correlation of the sideward opening aircraft door and its opening mechanism is conducted. Based on the position and orientation characteristic (POC) theory, the topological dimension constraint type characteristics of the sideward opening aircraft door mechanism is analyzed. It reveals that the door mechanism possesses two kinds of motion modes with one degree of freedom and different number of non-independent elements during the lifting and rotating processes. The study finds that the geometric constraint condition of the sideward opening aircraft door motion mode switching is that the rotation pair spacing of hinge arm mechanism is equal to the projection size of the parallel link mechanism length on the horizontal plane. The aircraft door drive combined with limiting stopper ensures the constant geometric constraint conditions, improves the accuracy of door mode switching and the stability of the opening process. Research on the opening process of the sideward opening aircraft door based on POC theory provides a new idea for aircraft door design.

Variable-DOF (or kinematotropic) mechanisms are a class of reconfigurable mechanisms that have varying degrees of freedom (DOF) in different motion modes and can be reconfigured without disassembly. However, the number of proposed variable-DOF multi-loop planar mechanisms is currently limited. This paper introduces a new 8-link variable-DOF planar mechanism that has five motion modes. Firstly, the 8-link variable-DOF planar mechanism is described. Then, reconfiguration analysis of the mechanism is performed using a hybrid approach that combines elimination and computer algebraic geometry methods. The analysis reveals that the 8-link mechanism has one 2-DOF motion mode and four 1-DOF motion modes. It can switch among three motion modes at four transition configurations and between two motion modes at the remaining four transition configurations. The paper also highlights the geometric characteristics of the mechanism in different motion modes. In contrast to variable-DOF planar mechanisms presented in the literature, the proposed 8-link mechanism has two inactive joints in one of its 1-DOF motion modes. Moreover, both closed-loop 4R kinematic sub-chains of the mechanism must appear as either a pair of parallelograms or a pair of anti-parallelograms in the same motion mode. As a by-product of this research, a method for factoring trigonometric functions in two angles is also proposed. [ABSTRACT FROM AUTHOR]

The stratospheric airship is taken as the research object, and the motion mode analysis of the stratospheric airship is carried out. The influence of key parameters such as the center of mass, the center of buoyance, and the aerodynamic stability moment on the motion mode of stratospheric airship are analyzed and summarized in detail. According to the simulation and analysis results, unlike high-speed and high-dynamic aircrafts such as airplanes, the motion modes of the stratospheric airship are hardly affected by the perturbation of aerodynamic stability moment; the perturbations of the vertical center of mass and the vertical center of buoyancy have a great influence on the pitch pendulum motion modes, and their parameter perturbations affect the frequency of the pitch pendulum motion and also the stability of the pitch pendulum motion; the axial mass center location perturbation not only changes the damping of pitch pendulum motion but also affects the frequency of the yaw motion attitude motion mode to a certain extent. [ABSTRACT FROM AUTHOR]

• The multi-mode mechanisms are divided into three types. • The principles of classification is expounded are discussed based on finite screw. • A determination method of multi-mode mechanism is proposed based on finite screw. To enrich the theoretical system of multi-mode mechanisms, a classification method and a determination method are proposed in this paper. From the perspective of configuration transformation, the multi-mode mechanisms are divided into two types: one based on lockable joints and the other based on the principle of bifurcated motion. Furthermore, the mechanisms based on the principle of bifurcated motion are categorized into two types: one based on the variable mobility branch and the other based on constraint singularity generated by branches. The principles of classification are expounded and the determination method is developed. The proposed classification and the determination methods of the multi-mode mechanism provide new insights for their analysis. [ABSTRACT FROM AUTHOR]

• Effect of fluid inertia and cavity structure on the motion behaviour were analysed. • Interesting new motion behaviours of swimmers in cavity have been discovered. • The captured phase diagrams were acquired to optimal the microfluidic devices. • Theoretical formulas were developed to reflect the separation performance. Based on the lattice Boltzmann method and the squirmer self-propulsion model, this paper focuses on the motion characteristics of three types of swimmers (neutral swimmer, puller, pusher) over a cavity in an inertial micro-channel. The effects of fluid inertia (Re f) and channel-cavity structural parameters (L d , L w) on the capture and separation of micro-swimmers are analysed. The results indicate that there are five motion modes of swimmer under low Reynolds number. As fluid inertia increases, three new motion modes emerge. Neutral swimmer is captured at low Re f , while the puller and pusher are captured at high Re f. Under a suitable cavity aspect ratio, the puller also exhibits an additional new trapping mode known as the circle loop trapping. Moreover, the pusher with large activity will behave differently at various Reynolds numbers. Ultimately, through data and theoretical analysis, theoretical formulas are developed to reflect the effect of cavity size and Reynolds number on the capture and separation performance through the phase diagram. By integrating the examination of diverse trapping behaviours of microwimmers within complex microchannel structures, this study significantly enhances our understanding of the complex motion of microwimmers in intricate flow environments, and facilitates the manipulation and control of manmade microwimmers. [Display omitted] [ABSTRACT FROM AUTHOR]

The scenario is very important to smartphone-based pedestrian positioning services. The smartphone is equipped with MEMS(Micro Electro Mechanical System) sensors, which have low accuracy. Now, the methods for scenario recognition are mainly machine-learning methods. The recognition rate of a single method is not high. Multi-model fusion can improve recognition accuracy, but it needs to collect many samples, the computational cost is high, and it is heavily dependent on feature selection. Therefore, we designed the DT-BP(decision tree-Bayesian probability) scenario recognition algorithm by introducing the Bayesian state transition model based on experience design in the decision tree. The decision-tree rules and state transition probability assignment methods were respectively designed for smartphone mode and motion mode. We carried out experiments for each scenario and compared them with the methods in the references. The results showed that the method proposed in this paper has a high recognition accuracy, which is equivalent to the accuracy of multi-model machine learning, but it is simpler, easier to implement, requires less computation, and requires fewer samples. [ABSTRACT FROM AUTHOR]

Traditional mobile robots face significant limitations in adaptability and performance due to their reliance on inflexible materials. These constraints have driven increasing interest in soft mobile robots, which leverage the inherent compliance and adaptability of soft materials to achieve complex functions. Among these materials, dielectric elastomers (DE) have emerged as a critical component, offering remarkable properties such as large deformation, rapid response, and high energy density when subjected to electrical excitation. This paper provides a comprehensive overview of dielectric elastomer actuators (DEA), detailing their working principles, material characteristics and common configurations. By drawing inspiration from natural organisms, we explore various motion modes such as crawling, walking and jumping, showcasing the development and potential of DEAs in creating highly adaptable and biomimetic mobile robots. Furthermore, We discuss the main challenges in the field, including potential solutions such as high drive voltages and limited output forces, to advance the practical application of DEA. This review aims to stimulate further research and innovation in the field of soft robotics, emphasizing the transformative potential of DEAs in advancing robotic mobility and functionality. [Display omitted] [ABSTRACT FROM AUTHOR]

Structural optimization has always been the main solution for increasing the stability of flexible screens. The bending method used to test a flexible display screen is an important factor in assessing the functionality and practicability of the electronic device. The bending mode of the display screen impacts the screen service life. In this study, 2D simulation models with different bending radii, bending directions, and bending times were constructed in ABAQUS and compared to determine the effects on the flexible screen from changing the stress value, the location of the stress concentration area and the deformation state of the screen under U- and water-drop-shaped bending. The simulation results show that U-shaped bending severely strains the junction between the bent and unbent areas of a model, whereas water-drop-shaped bending can avoid such problems. In addition, the results of multiple bending experiments were used to determine an appropriate reserved length of r=2.1~2.4 mm for a model under water-drop-shaped bending.

Variable-DOF (or kinematotropic) mechanisms are a class of reconfigurable mechanisms that have varying degrees of freedom (DOF) in different motion modes and can be reconfigured without disassembly. However, the number of proposed variable-DOF multi-loop planar mechanisms is currently limited. This paper introduces a new 8-link variable-DOF planar mechanism that has five motion modes. Firstly, the 8-link variable-DOF planar mechanism is described. Then, reconfiguration analysis of the mechanism is performed using a hybrid approach that combines elimination and computer algebraic geometry methods. The analysis reveals that the 8-link mechanism has one 2-DOF motion mode and four 1-DOF motion modes. It can switch among three motion modes at four transition configurations and between two motion modes at the remaining four transition configurations. The paper also highlights the geometric characteristics of the mechanism in different motion modes. In contrast to variable-DOF planar mechanisms presented in the literature, the proposed 8-link mechanism has two inactive joints in one of its 1-DOF motion modes. Moreover, both closed-loop 4R kinematic sub-chains of the mechanism must appear as either a pair of parallelograms or a pair of anti-parallelograms in the same motion mode. As a by-product of this research, a method for factoring trigonometric functions in two angles is also proposed.

The stratospheric airship is taken as the research object, and the motion mode analysis of the stratospheric airship is carried out. The influence of key parameters such as the center of mass, the center of buoyance, and the aerodynamic stability moment on the motion mode of stratospheric airship are analyzed and summarized in detail. According to the simulation and analysis results, unlike high-speed and high-dynamic aircrafts such as airplanes, the motion modes of the stratospheric airship are hardly affected by the perturbation of aerodynamic stability moment; the perturbations of the vertical center of mass and the vertical center of buoyancy have a great influence on the pitch pendulum motion modes, and their parameter perturbations affect the frequency of the pitch pendulum motion and also the stability of the pitch pendulum motion; the axial mass center location perturbation not only changes the damping of pitch pendulum motion but also affects the frequency of the yaw motion attitude motion mode to a certain extent.

The magnitude of the external loads and impacts on the mobile transport and technological machine depend on the current motion mode and its parameters. The article presents approaches to the simulation modeling of the motion modes of a mobile transport and technological machine. Modeling involves two stages. In the first stage, using simulation model are determined by parameters of the motion (a rotation of different modes of movement, machine speed, the duration of modes). In the second – with the help of mathematical model of dynamics examines the workflows of mobile transport technological machine. The results of the simulation are a set of values of the motion parameters, as well as the implementation of the dynamic loading process.

Owing to autonomy and continuity, a pedestrian navigation system (PNS) has been widely deployed, which is based on the micro electro-mechanical system inertial measurement unit (MEMS-IMU) and the strapdown inertial navigation system (SINS). However, altitude information cannot be effectively obtained in this system by the double integral of vertical acceleration because of the altitude channel divergent of SINS. The study is aimed at improving the accuracy and robustness of altitude estimation through a novel method based on foot-mounted MEMS-IMU. More specifically, the proposed method exploits the adaptive network-based fuzzy inference system (ANFIS) to recognize vertical motion modes including horizontal, downstairs, and upstairs movements. Then, the pseudo height model based on both motion modes and the stair height is constructed for stair walking with different height. Finally, the pseudo measurements from the pseudo height model are integrated with the data from motion prediction through the extended Kalman filter (EKF). Experimental results show that the overall classification accuracy of ANFIS can reach up to 99.1%. Since ANFIS is utilized to assist height estimation, the cumulative height error accounts for about 1.2% over a total height of 44 m when a pedestrian walks up and down six floors without external facility and barometric pressure support. It is concluded that the ANFIS-based height estimation method can achieve better vertical positioning performance for PNS than the existing approaches in terms of accuracy and robustness.

The scenario is very important to smartphone-based pedestrian positioning services. The smartphone is equipped with MEMS(Micro Electro Mechanical System) sensors, which have low accuracy. Now, the methods for scenario recognition are mainly machine-learning methods. The recognition rate of a single method is not high. Multi-model fusion can improve recognition accuracy, but it needs to collect many samples, the computational cost is high, and it is heavily dependent on feature selection. Therefore, we designed the DT-BP(decision tree-Bayesian probability) scenario recognition algorithm by introducing the Bayesian state transition model based on experience design in the decision tree. The decision-tree rules and state transition probability assignment methods were respectively designed for smartphone mode and motion mode. We carried out experiments for each scenario and compared them with the methods in the references. The results showed that the method proposed in this paper has a high recognition accuracy, which is equivalent to the accuracy of multi-model machine learning, but it is simpler, easier to implement, requires less computation, and requires fewer samples.

The article is devoted to influence of the clay thixotropic solutions on the strength of resistance to movement of the earthmoving machines' working elements.The forces of resistance to the movement of a flat plate, a smooth cylinder and real working bodies in a clay solution for various modes of solution flow (bingamian, pseudo-laminar and turbulent) are established.Mathematical models of movement of the earthmoving machines working elements in clay solution are developed and investigated.Dynamics of the working element of an earthmoving machine movement in a clay solution is studied. Dependence of the feed force, torque and dynamic coefficient on the resistance forces, acting on the working body from the clay solution, is established.

The article is devoted to influence of the clay thixotropic solutions on the strength of resistance to movement of the earthmoving machines' working elements. The forces of resistance to the movement of a flat plate, a smooth cylinder and real working bodies in a clay solution for various modes of solution flow (bingamian, pseudo-laminar and turbulent) are established. Mathematical models of movement of the earthmoving machines working elements in clay solution are developed and investigated. Dynamics of the working element of an earthmoving machine movement in a clay solution is studied. Dependence of the feed force, torque and dynamic coefficient on the resistance forces, acting on the working body from the clay solution, is established. [ABSTRACT FROM AUTHOR]

In order to increase reliability and accuracy of robot manipulators or other construction equipment used for lifting operations an optimum dynamic mode for moving its boom system has been calculated in the paper. Results of the research have made it possible to construct a mathematical model for manipulator movement and obtain kinematic characteristics of the optimum dynamic mode. While determining the optimum dynamic motion mode, a criterion action has been used as an optimization criterion which represents a time integral with an integrand function expressing a dynamic component of manipulator drive power. Functions for changing kinematic characteristics of an manipulator boom have been calculated when it moves from one predetermined position to another one and which correspond to optimum dynamic mode of motion. Search for an optimum motion mode has been performed by minimizing the optimization criterion using the Euler–Poisson equations. In this case a generalized angle of rotation has been used which permits to relate movement of the boom and oscillations of its support part. As a linking component differential equations of system motion have been also applied, in which relationships between an oscillation angle, rigidity of a manipulator support, and its mass-geometric characteristics have been recorded. Results of the work can be useful for refinement and improvement of existing engineering methods for calculating the drive mechanisms of manipulators both at design/construction stages and in real operation modes, and the results can also be used while making design or improvement of similar executive mechanisms for construction equipment and robots.

Human motion mode detection is of great value in evaluating motor ability. In this study, a method of human motion mode detection based on an acceleration sensor was characterized. A human motion mode detection system was designed using the standard deviation, peak, valley and peak-valley interval as characteristic values and a particle swarm optimization – support vector machine (PSO-SVM) algorithm as the detection method. The measurements of 10 subjects in static, walking and running stages were collected and evaluated. The experimental results showed that the static, walking and running detection accuracy values were 96%, 90% and 92% respectively, and the overall value was 94%. Using the same number of samples, the detection accuracy of SVM was 82.57%, while that of PSO-SVM was 93.1%, which had the highest reliability. This study demonstrates the validity of the human motion mode detection method based on an acceleration sensor which can accurately detect static state, walking and running, and the method is worth further promotion and application. [ABSTRACT FROM AUTHOR]

Hybrid underwater glider combines motion modes of traditional autonomous underwater glider and those of autonomous underwater vehicles. Different motion modes need different flight performance, including flight efficiency, static stability, and maneuverability. Conventional hybrid underwater glider with fixed wings can't achieve optimal flight performance in one flight mission demanding various motion modes. In this article, controllable wings for hybrid underwater glider Petrel II are designed. Angle of attack, sweep angle, and aspect ratio of controllable wings can be changed to adapt to different motion modes. Kinematics and dynamics models of Petrel II are established based on multibody theory. Motion simulations of Petrel II with different wing configurations are conducted in three motion modes, including glide motion, spiral motion, and horizontal turning motion. The simulation results show the impact of wing parameters on flight performance. Field trials demonstrate that the controllable wings can improve the flight performance. [ABSTRACT FROM AUTHOR]