Wheel Radius Research Articles

A light-fueled self-rolling unicycle with a liquid crystal elastomer rod engine

Active materials hold substantial potential for self-sustaining motion, however, the dependency on movable light or extensive area illumination in current structures often restricts the design and practical deployment of such active machines. In this study, we report a novel zero-energy-mode, self-rolling unicycle equipped with a liquid crystal elastomer rod engine, which fueled by a fixed, small-area light source. By employing an elaborate dynamic model for liquid crystal elastomer, we derive the lateral curvature of the liquid crystal elastomer rod and the driving moment necessary for the unicycle's self-rolling. The study results demonstrate that the self-rolling of the unicycle is driven by a moment induced by the shift in the center of gravity of the curved liquid crystal elastomer rod. Our numerical simulations indicate the presence of a supercritical Hopf bifurcation point delineating the transition between the self-rolling mode and the static mode within the unicycle system. Additionally, the rolling velocity of the unicycle relies on a handful of key system parameters, notably including light intensity, light penetration depth, length of the liquid crystal elastomer rod, rolling friction coefficient, total mass of the unicycle, and wheel radius of the unicycle. The experimental validation of a self-rolling unicycle with zero-energy-mode has been conducted. The self-rolling unicycle constructed in this paper has excellent characteristics of simple structure, zero-energy-mode, horizontal constant light source, and small area light source, providing valuable insights for the utilization of photoresponsive liquid crystal elastomer rods in soft robotics, medical devices, energy harvesting systems, and actuators.

AN EXPERIMENTAL INVESTIGATION ON NOVEL SEGMENTED OMNI WHEELED HYBRID MOBILE ROBOT TO ASSESS OBSTACLE CLIMBING CAPABILITY

Abstract This article introduces a novel quadrupedal hybrid mobile robot with a segmented omni wheel design capable of climbing obstacles of height greater than its wheel radius. The unique wheel design comprises of two parallel coaxial 240-degree segmented omni wheels per leg with independent offset angle control. The transformation from wheel to leg mode and vice versa can be seamlessly achieved by controlling the offset angle between the segmented omni wheels. A series of experiments are carried out to evaluate the robot's performance for obstacle climbing capability utilizing various wheel end effector designs, and a comparative analysis is presented. The results indicate that the obstacle climbing capability of segmented omni wheel design with zero offset angle is improved by 40.7% compared to standard wheel and the unique wheel design configuration facilitates seamless staircase climbing capability without any complex control scheme. In addition, statistical studies using Taguchi method and ANOVA are performed on the experimental findings. A linear regression model to predict power consumption has been developed and the significant factors influencing the robot's power consumption and stability are presented.

Kinematics modeling of the gear-based crank mechanism engine regardless of the compressions ratio variations.

In this work, geometric and kinematic modeling of the gear-based crank mechanism engine (GBCM) was performed. To this aim, a mechanical approach based on projective computational methods and mechanism theory laws is applied, to which a parametric study has allowed a conclusion on the geometrical and kinematic behaviors of the moving links. The study concluded that the kinematic quantities at connecting rod head are one-half of those at the piston top head. The extrinsic behavior like the stroke of the connecting rod head is twice the crank radius and the piston kinematic are identical to the conventional engine with the same crankshaft ratio regardless of the compression ratio and any gear wheel radius. Hence, all the extrinsic kinematic properties of a classic crankshaft mechanism of the fixed compression ratio engine remain valid for a gear-based crank mechanism engine and can be used for dynamic calculation purposes.

The Variational Iteration Method for a Pendulum with a Combined Translational and Rotational System

Abstract The dynamic analysis of complex mechanical systems often requires the application of advanced mathematical techniques. In this study, we present a variation iteration-based solution for a pendulum system coupled with a rolling wheel, forming a combined translational and rotational system. Furthermore, the Lagrange multiplier is calculated using the Elzaki transform. The system under investigation consists of a pendulum attached to a wheel that rolls without slipping on a horizontal surface. The coupled motion of the pendulum and the rolling wheel creates a complex system with both translational and rotational degrees of freedom. To solve the governing equations of motion, we employ the variation iteration method, a powerful numerical technique that combines the advantages of both variational principles and iteration schemes. The Lagrange multiplier plays a crucial role in incorporating the constraints of the system into the equations of motion. In this study, we determine the Lagrange multiplier using the Elzaki transform, which provides an effective means to calculate Lagrange multipliers for constrained mechanical systems. The proposed solution technique is applied to analyse the dynamics of a pendulum with a rolling wheel system. The effects of various system parameters, such as the pendulum length, wheel radius and initial conditions, are investigated to understand their influence on the system dynamics. The results demonstrate the effectiveness of the variation iteration method combined with the Elzaki transform in capturing the complex behaviour of a combined translational and rotational system. The proposed approach serves as a valuable tool for analysing and understanding the dynamics of similar mechanical systems encountered in various engineering applications.

Analysis of the parameters of technological material sprinkling devices of special road vehicles (ꞷδ=const): MAN CLA 18.280 4x2 BB CS45

In this article, the size of the wheel radius of the special road vehicle (MAN CLA 18.280 4x2 BB CS45), which is widely used to increase the economic and material efficiency in the elimination of slippage on the road surface in the winter season, and to ensure traffic safety, and the height of the wheel installation o It is studied how far the technological material can be sprayed when the rotation speed is constant. Process material spreaders have equipment that is permanently attached to vehicle chassis or trailers or can be quickly detached. The supply of technological material (salt-sand) to the spreader disk, the forces acting on the technological material (salt-sand) particle during the rotation of the spreader disk were considered. The dependence of the particle flight range when the radius of the scattering disk, the height of the disk, and the angular velocity of the scattering disk have a constant value have been considered. The impact of technological material particles on the distance of a particle flying from the outer edge of the disk and falling to a certain distance, the radius of the disk, the height of the disk above the level of the carriageway, the value of the angular velocity of the disk, and the width of spraying relative to the road surface; the diameter of the sprinkling disk and the height of the sprinkling disk: the dependence of the density of sprinkling relative to the road surface, the speed of the main machine, and the speed of material delivery were studied.

Design of A Novel Wheel-Legged Robot with Rim Shape Changeable Wheels

The wheel-legged hybrid structure has been utilized by ground mobile platforms in recent years to achieve good mobility on both flat surfaces and rough terrain. However, most of the wheel-legged robots only have one-directional obstacle-crossing ability. During the motion, most of the wheel-legged robots’ centroid fluctuates violently, which damages the stability of the load. What’s more, many designs of the obstacle-crossing part and transformation-driving part of this structure are highly coupled, which limits its optimal performance in both aspects. This paper presents a novel wheel-legged robot with a rim-shaped changeable wheel, which has a bi-directional and smooth obstacle-crossing ability. Based on the kinematic model, the geometric parameters of the wheel structure and the design variables of the driving four-bar mechanism are optimized separately. The kinetostatics model of the mobile platform when climbing stairs is established to determine the body length and angular velocity of the driving wheels. A prototype is made according to the optimal parameters. Experiments show that the prototype installed with the novel transformable wheels can overcome steps with a height of 1.52 times of its wheel radius with less fluctuation of its centroid and performs good locomotion capabilities in different environments.

Numerical simulation and parameter optimization of Coriolis force scale measurement process based on DEM

The Coriolis force method is a recently developed and highly regarded direct measurement technique that enables high-precision measurement of bulk materials. The operational parameters and variations thereof directly influence the measurement accuracy of the equipment. In this study, a measurement correction coefficient is introduced to improve the calculation method for mass flow rate of the materials. The DEM is employed to simulate the motion of particle groups within the Coriolis force scale under different parameters, and the effects of various structural and operational parameters on the measurement results are compared. The research findings indicate that a lower rotational speed leads to more stable instantaneous measurement results, although the measurement error is relatively large. When the rotational speed exceeds 300 rpm, the measurement error remains within 15%. For materials with a radius of 1–2 mm, the variation range of precision error is approximately 0.4%. Among the structural parameters, the radius of the measurement wheel has the most significant impact on the measurement results, wherein a larger measurement wheel radius corresponds to a smaller measurement error. The horizontal angle of the blades follows as the next influential parameter, with a clockwise rotation and a horizontal angle of 30° resulting in a measurement error below 2%.

Trajectory planning of deep-cutting laser profiling of superabrasive profile grinding wheels

The low profiling efficiency is the key barrier to the industrial application of laser dressing technology for profile grinding wheels. In this paper, the trajectory planning method of deep-cutting laser profiling was proposed for the first time, the theoretical model of the energy distribution of the Gaussian laser beam on the surface of the profile grinding wheel was established, and the effect of this method on improving the profiling efficiency of superabrasive profile grinding wheel was systematically studied. Through comparative experiments, it was confirmed that the trajectory planning method could effectively improve the profiling efficiency of the V-shaped grinding wheel, and it was found that the smaller the tip angle, the greater the efficiency improvement. The change of grain size will lead to the change of grain removal method, which will affect the profiling efficiency of V-shaped grinding wheel, but it has little influence on the profiling accuracy. The V-tip arc radius of the diamond grinding wheel with a particle size of 20–180 μm after laser profiling could be controlled between 10 and 20 μm, which was difficult to achieve by mechanical or electrical dressing method. The trajectory planning method could also significantly improve the profiling efficiency of convex/concave arc-shaped grinding wheels, and the greater the arc radius or chord-to-diameter ratio of the grinding wheel, the greater the efficiency improvement. Even though convex/concave arc-shaped grinding wheels were the same size, their profiling efficiency and material removal efficiency were quite different. For grinding wheels with different arc radii or chord-to-diameter ratios, different process strategies should be selected during laser profiling to ensure a comprehensive balance between efficiency, accuracy and quality.

Road friction coefficient estimation under low longitudinal, lateral and combined excitation

On the way to autonomous driving more and more advanced driver assistance systems (ADASs) are developed to increase safety and comfort. These functions require additional quantified information about the environment, for example information about the current road condition, which a human driver would perceive intuitively. In this paper, a road condition estimation, described by a road friction coefficient, is developed using a second order divided differences filter in combination with estimates of the time varying parameters, namely the dynamic wheel radius and the tire stiffness. Using real measurement data of commercial vehicles, the estimation algorithm is compared to a static and less complex longitudinal friction coefficient estimator. The comparison shows good results for both estimators with differences at low excitation and during cornering maneuvers.

ЭЛЕКТРОГИДРОМЕХАНИЧЕСКАЯ МОБИЛЬНАЯ ПЛАТФОРМА

Vaulting when setting up dosing organs worsens the quality of the feed dispenser, especially when issuing small doses. The use of a mobile electrohydromechanical platform as part of the feed dispenser allows you to reduce the cost of materials in the feed distribution line and expand the functionality of the feeding equipment. The amount of feed mixture dispensed to the feeder by such feed dispensers can be changed by controlling the speed of movement of the electrohydromechanical platform along a continuous row of feeders, which makes it possible to neutralize the violation of the performance of dosing organs when issuing small doses of feed. The analytical dependence of determining the effect on the norm of the feed delivery rate on the performance of the dosing organ and the parameters of the electrohydromechanical mobile platform (the performance of the dosing device, the parameters of the chassis and a number of others) was obtained. The pneumatic tire of the electrohydromechanical mobile platform is subject to deformation. The rolling radius of the pneumatic wheel must be taken into account when determining the actual speed of movement of the mobile electrohydromechanical platform. The changing mass of feed in the feed dispenser during distribution changes the rolling radius of the wheel, as well as the amount of feed dispensed into a group or continuous feeder. A methodology and experimental setup for studying the change in the rolling radius of a wheel from a vertical load consisting of an electrohydromechanical platform supported by a wheel on a lever connected to a weighing device have been developed. The levels of variation and factors (pressure in the pneumatic tire and the amount of vertical load), as well as the evaluation criterion (the amount of deformation of the pneumatic tire, determined by the rolling radius of the pneumatic tire) are given. The experimental dependences obtained are nonlinear in nature. Studies have shown that when the pressure in the tire of the wheel is more than 1.5 MPa, with an increase in the vertical load of more than 150 kg per wheel, the change in the translational speed of the feed dispenser and the rolling radius of the wheel are within the permissible repartitions and do not exceed 5%.

The Implementation of the Integrated STEAM Approach to Improve Students' Interest in Science

The study aimed to analyze indigenous scientific knowledge into scientific knowledge through the STEAM approach. Interesting online learning can be done by integrating the local culture of the Plancungan Village. This research uses the Quantitative Descriptive method. Based on research at seven schools in Ponorogo found 83,3% of teachers never used the local culture because teachers know no understands the local culture of the Plancungan village in science material. Respondents were 62 students from Junior High School 1, Junior High School 2, and Junior High School 3. 37,74% of students know this local culture. The value of local culture is contained in the process of making pottery, namely character, aesthetic, historical, and environmental values. STEAM analysis, including science on the process of making pottery, requires a tool in the form of a turntable called "Perabot". This turntable is a form of Simple Plane. Simple Planes are tools that can facilitate human work. The math is in the Mechanical Advantage of the "Perabot" which can be calculated by dividing the wheel's radius by the axle's radius. Engineering on the body has the greatest ratio of volume to overall proportion. The moth is smaller than the neck, which is adapted to its function. Traditional pottery-burning technology uses a field stove with husk, straw, and bamboo as fuel. The art of pottery can be seen in form, color, and function. STEAM analysis on the pottery-making process can increase students' interest in science. The student's interest in learning science obtained an average N-gain of 0.70 with high criteria. The resulting STEAM analysis can also be applied to e-modules, e-learning, e-books, etc.

A deep learning approach for optimize dynamic and required power in electric assisted bicycle under a structure and operating parameters

The purpose of this research is to study how the operating and structure parameter affect the dynamic, require power and electric consumption of electric assisted bicycle (EAB). The paper applied a combined an artificial neural network (ANN) with genetic algorithm (GA) method to predict the required power, electric consumption of EAB and find an effective performance area. The MATLAB-Simulink simulation model is established to create 1000 data point, that is applied in an ANN for training, testing and verifying. The ANN-GA method is applied to identify the optimized required power and electric consumption under four typical slope grades in the area of (0–0.65%), four typical wheel radius in the area of (0.3–0.0.39 m), four typical frontal areas in the range of (0.423–1.323 m2), four typical speed levels from speed level 1 to speed level 4. After the ANN is trained, it is applied into the genetic algorithm to identify the effective performance. The prediction results reflect the major physical mechanism that governs ES performance and are validated against the MATLAB-Simulink simulation model. Additionally, the electric assisted bicycle can reach an effective performance area at 27.16 km/h with the optimized required power of 545.5 W at slope grade of 0%, wheel radius of 0.39 m, speed level 4, frontal area of 0.423 m2. The results show that the ANN-GA method is suitable to identifying structure and operating parameters including various slope grades, frontal areas, wheel radius, speed level for optimizing effective performance of EAB, which contributes a helpful method for EAB design and control. Beside that, the experimental test was conducted on real road test at Taehwa river to verify the simulated results. The experiment results and simulation results have the same trend at the same conditions. (The short version of the paper was presented at ICAE2022,Bochum, Germany,Aug 8–11, 2022. This paper is a substantial extension of the short version of the conference paper.)

Study the effect of wheel radius on the Electric Motorbike's performance through a simulation model

The purpose of this research is to study how wheel radius affects the Electric Motorbike's performance. Based on mathematical models and the MATLAB SIMULINK software, an electric motorcycle simulation model, including a dynamic model and a battery model, was created to achieve this goal. The simulation model is used to determine the speed, thrust torque, and power consumption characteristics with changing wheel radius. The simulation results show that when changing the wheel radius from 0.1 m to 0.25 m, the maximum speed increases from 23 to 52 km/h, the travel distance increases from 400 to 850 m after 60 seconds of simulation time, and the battery voltage decreases from 59.9 to 57.7 V while the engine power consumption increases.

Effects of the Structure and Operating Parameters on the Performance of an Electric Scooter

The research objective is to approach the dynamic and consumed electrical energy of an electric scooter by varying the key input parameters, including rider mass, electric scooter mass, wind speed, wheel radius, and slope grade. A simulation model of an electric scooter was applied in a MATLAB-Simulink environment to investigate the scooter velocity, required power, battery voltage, and propulsion torque of the e-scooter. It was established by employing mathematical equations during the of electric scooters. The study found that the scooter velocity and electricity consumption were optimized by 3.9% and 0.08%, respectively, when the scooter weight decreased from 26 to 10 kg. The scooter velocity, electricity consumption, and required power decreased by 23.2%, 0.55%, and 8.56%, respectively, when the slope grade decreased from 1.15% to 0%. Following a wind speed reduction from 4 to 0 m/s, the consumed electricity and required power were optimized by 0.2% and 5.5%, respectively. The consumed electricity increased by 0.2% and the scooter velocity and required power significantly increased by 36.5% and 34.3% when the wheel radius increased from 0.105 to 0.185 m. Furthermore, the e-scooter could achieve an effective performance with a weight of 10 kg, wheel radius of 0.185 m, wind speed of 0 km/h, slope grade of 0%, and minimal rider weight. The simulation results showed that the scooter’s effective performance range and consumed electrical energy could be optimized by suitably adjusting the key structures and operating parameters. To support this research, a concurrent experiment investigated the dynamic characteristics and electricity consumption of the electric scooter during operation. The experimental and simulated results had the same patterns in similar initial conditions.

벽 등반 드론 자세에 따른 모듈형 영구자석 휠-레그의 부착력

Improving battery performance is crucial for increasing drone flight time. However, developing individual parts can also enhance mission performance and extend operating time. By attaching a drone to a wall instead of hovering in the air, the operating time and range of task performance can be extended. This study focuses on the adhesion force of a modular permanent magnet wheel leg for wall climbing drones. The wheel leg comprised several spokes without a rim. It could climb obstacles higher than wheel radius and provide a large adhesion area. An equation for the adhesion force of the wheel leg was derived, considering mechanical factors such as drone size, inclination of the ferromagnetic wall, and drone posture. A simple experimental model was created to verify the validity of the adhesive force equation. The effectiveness of the derived equation was confirmed by experimentally measuring the angle of the ferromagnetic wall that losT adhesion according to mechanical factors and comparing it with the derived adhesion force.

Numerical Simulation Investigation on Parameter Optimization of Deep-Sea Mining Vehicles

The four-track walking mining vehicle can better cope with the complex terrain of cobalt-rich crusts on the seabed. To explore the influence of different parameters on the obstacle-crossing ability of mining vehicles, this paper took a certain type of mine vehicle as an example and establish a mechanical model of the mine vehicle. Through this model, the vehicle’s traction coefficient variation could be analyzed during the obstacle-crossing process. It also reflected the relationship between the obstacle-crossing ability and the required traction coefficient. Many parameters were used for this analysis including the radius of the guide wheel radius, ground clearance of the driving wheel, the dip angle of the approaching angular and the position of centroid. The result showed that the ability to cross the obstacles requires adhesion coefficient as support. When the ratio between obstacle height and ground clearance of the guide wheel was greater than 0.7, the required adhesion coefficient increased sharply. The ability to cross obstacles will decrease, if the radius of the guide wheel increases, the height of the driving wheel increases or the dip angle of the approaching angular increases. It was most beneficial to cross the obstacle when the ratio of the distance between the center of mass and the front driving wheel to the wheelbase is between 0.45‒0.48. The results of this paper could provide reference for structural parameter design and performance research for mining vehicles.

Overcoming Obstacles Using Tail STAR: A Novel Sprawling Robot With a Two-Joint Tail

This paper presents Tail STAR (TSTAR), a novel reconfigurable robot with an active two-link tail. TSTAR is also fitted with a sprawling mechanism that lets it run either upright or inverted and change its height. The tail enables the robot to move its center of mass (COM) forwards or backwards and extend its length, provides it with more surface contact points, and increases its climbing capabilities. After presenting a kinematic model of the robot, a quasi-static analysis is presented that aims at optimizing the design of the robot and evaluating its motor requirements, climbing conditions and limitations. Experiments then show that the combination of the sprawling and tail mechanisms enables the TSTAR to overcome extremely challenging obstacles, climb high steps (6 times its wheel radius), bridge gaps equal to its own body length, and flip over to switch between its whegs and wheels to operate on very different terrains such as dirt, stones and grass (see attached video).

A Novel Transformable Leg-Wheel Mechanism

Abstract In this paper, a novel transformable leg-wheel mechanism is proposed. It has three active joints, among which the hip roll joint is directly driven, the hip pitch joint is driven by gear transmission, and the knee joint is driven by synchronous belt transmission. All the actuators are mounted on the body to reduce the weight of the leg-wheel mechanism as possible, so that the motion of the leg-wheel mechanism will be slightly affected by the inertia. The proposed mechanism has two characteristics, the big wheel radius and the reduced actuator. The design and kinematics modeling methods of the leg-wheel mechanism are described. A half-a-heart shape trajectory is proposed to plan the foot motion of the leg-wheel mechanism in the legged locomotion. To make the locomotion mode transition smooth, the transition strategy is designed. Simulation and experimental results verify the feasibility of the proposed leg-wheel mechanism.

Design and Analysis of a Wheel−Leg Hybrid Robot with Passive Transformable Wheels

This paper proposes a novel wheel−leg hybrid robot that can be applied on both flat and rugged terrains, it utilizes two passive transformable symmetrical wheels that combine the stability of the circular wheel and the obstacle climbing ability of the legged wheel. To minimize the number of actuators, the transformation process of the wheel is designed to be triggered passively when in contact with the obstacles. A new triggering mechanism is employed to eliminate the adverse effect of the robot’s weight on the transformation torque. The parameters of the wheel are optimized to maximize the climbing ability in low-friction conditions. The robot’s body length and angular velocity are also tuned based on the dynamic model during the obstacle climbing process. The simulation experiment results show that the robot can switch modes stably on terrain with a friction coefficient as low as 0.2, and can climb over an obstacle 3.9 times as tall as its wheel radius.

The effect of test track wheel radius on the evaluation of linear eddy current braking performance of high-speed maglev train

To study the braking performance of linear eddy current brake (LECB) for high-speed maglev trains, experimental studies are usually carried out using a track wheel with a finite radius and a track wheel eddy current brake (TWECB) with a certain radius of curvature. However, the geometrical differences between the two braking methods due to the track radius will lead to differences in their effective excitation air gap during operation. Therefore, the excitation air gap model and eddy current braking force model of TWECB and LECB are developed in this study. Through the excitation air gap model and eddy current braking force model proposed in this paper, the difference in braking performance between TWECB and LECB in the velocity domain and operating air gap domain can be obtained for different track radii. The correctness of the finite element analysis (FEA) method is verified by experimental data, and the eddy current density, braking force and air gap flux density formed by eddy current braking at different track radii are analysed using the finite element method. The results show that an appropriate test track radius can significantly improve the accuracy of TWECB in estimating the braking performance of LECB.