Conventional Wheel Research Articles

Experimental investigation for a non-adiabatic desiccant wheel with a concentric structure at low regeneration temperatures

The desiccant wheel-based air-conditioning system has been considered to be an effective alternative to conventional air-conditioning systems to reduce energy consumption in buildings. However, the adsorption and carryover heat released during the wheel’s working process both significantly restrict dehumidification and energy performance. Moreover, it is also difficult to apply a low temperature of thermal energy, including solar thermal energy and waste heat, in the desiccant wheel-based air-conditioning system. To improve the dehumidification and energy performance, and use a low temperature of thermal energy, this study designed, constructed and tested a non-adiabatic solid desiccant wheel, which is based on a concentric ring design. The wheel’s structure was fabricated from Nylon, using three-dimensional technology with polymer desiccant materials inserted into the channels between each of two rings. Then, cooling water was brought into the narrow passages inside the rings on the process air side of the wheel, with the aim of transforming the dehumidification process from quasi-adiabatic to quasi-isothermal. A series of experiments were then conducted to investigate this system’s performance under various operating conditions. The measurements showed that, when the inlet air and cooling water temperatures were 25 °C and 24 °C, respectively, the dehumidification performance of the new wheel was approximately the same as that of a conventional desiccant wheel. However, when the inlet temperature of the process air was 35 °C, the dehumidification process of the new wheel was very close to the ideal for a desiccant wheel – an isothermal dehumidification process. In this condition, the enthalpy effectiveness of the tested wheel was also 11% higher than that of a conventional wheel.

Lightweight Wheel Bearing with Dissimilar Materials for Vehicle

<div class="section abstract"><div class="htmlview paragraph">Limited fossil fuel resources, air pollution, and global warming all drive strengthening of fuel economy and vehicle emission standards globally. Much R&D continues to be dedicated to improve fuel efficiency of automobiles and to reduce exhaust gasses. These include improvement of engine/driveline performance for higher efficiency, development of alternative energy, and minimization of air resistance through aerodynamic design optimization. OEM weight reduction-focused research has extended into chassis components (steering knuckle, brakes, control arms, etc.) in sequence from body-in-white(BIW). Wheel bearings, one of the core components of a driveline and part of a vehicle’s unsprung mass, are also being required to reduce weight. Conventionally, wheel bearings have achieved “lightweighting” primarily through design optimization methods. They have been highly optimized today using steel based materials. Opportunities for further mass optimization are increasingly limited and so the focus of this study is integration of lighter-materials into steel bearing components for weight savings. Both aluminum and CFRP were considered in the study for partial integration into the steel hub flange which interfaces directly with the wheel. The application of lightweight materials was targeted on the specific area of the hub which is relatively less affected by impact loads. Hot forging and compressive molding were applied to induce denser bonding of the dissimilar materials. The slope angle design having an inverse draft at the combined boundary was applied to reinforce physical bonding and to enhance joint integrity. In addition, a Zinc-based coating was partially applied on the surface of the combined boundary to protect against galvanic corrosion between dissimilar materials. Bearings containing the new composite hubs achieved a 20% weight reduction compared to conventional wheel bearings made of full steel.</div></div>

Flatness-based control scheme for hardware-in-the-loop simulations of omnidirectional mobile robot

Omnidirectional robots offer better maneuverability and a greater degree of freedom over conventional wheel mobile robots. However, the design of their control system remains a challenge. In this study, a real-time simulation system is used to design and develop a hardware-in-the-loop (HIL) simulation platform for an omnidirectional mobile robot using bond graphs and a flatness-based controller. The control input from the simulation model is transferred to the robot hardware through an Arduino microcontroller input board. For feedback to the simulation model, a Kinect-based vision system is used. The developed controller, the Kinect-based vision system, and the HIL configuration are validated in the HIL simulation-based environment. The results confirm that the proposed HIL system can be an efficient tool for verifying the performance of the hardware and simulation designs of flatness-based control systems for omnidirectional mobile robots.

Towards the Development of a Learning-Based Intention Classification Framework for Pushrim-Activated Power-Assisted Wheelchairs.

There has been a growth in the design and use of power assist devices for manual wheelchairs (MWCs) to alleviate the physical load of MWC use. A pushrim-activated power-assisted wheel (PAPAW) is an example of a power assist device that replaces the conventional wheel of a MWC. Although the use of PAPAWs provides some benefits to MWC users, it can also cause difficulties in maneuvering the wheelchair. In this research, we examined the characteristics of wheelchair propulsion when using manual and powered wheels. We used the left and right wheels' angular velocity to calculate the linear and angular velocity of the wheelchair. Results of this analysis revealed that the powered wheel's controller is not optimally designed to reflect the intentions of a wheelchair user. To address some of the challenges with coordinating the pushes on PAPAWs, we proposed the design of a user-intention detection framework. We used the kinematic data of MWC experiments and tested six supervised learning algorithms to classify one of four movements: "not moving", "moving straight forward", "turning left", and "turning right". We found that all the classification algorithms determined the type of movement with high accuracy and low computation time. The proposed intention detection framework can be used in the design of learning-based controllers for PAPAWs that take into account the individualized characteristics of wheelchair users. Such a system may improve the experience of PAPAW users.

Evaluation of five steering input devices in terms of muscle activity, upper body kinematics and steering performance during heavy machine simulator driving

Work related upper body musculoskeletal symptoms and disorders constitute a major problem for operators of heavy machinery. Steering input devices mediate risk factors of upper body musculoskeletal disorders. Little research has been conducted to compare the multiple commercially available steering input devices in a multi-faceted approach. The present study evaluated five commonly used steering input devices (conventional steering wheel, fast steering wheel, miniature steering wheel, first-order joystick and second-order joystick) in terms of muscle activity, upper body kinematics and steering performance during heavy machine simulator driving. Fifteen healthy males novice to operation of heavy machinery completed five laps on a simulated track with each steering input device. Results showed a generally lower muscle activity when using the joysticks. The conventional and fast steering wheel increased mean wrist and shoulder flexion/extension angles and participants spent more time in wrist flexion/extension angles corresponding to moderate and poor comfort levels. An increased elbow protonation angle was found for the three steering wheels compared to the joysticks. The conventional steering wheel showed slowest track completion time and was subjectively ranked worst. The first-order joystick was ranked highest but also showed the highest amount of steering reversal rates, posing a risk of increased repetitiveness. Overall, the second-order joystick is considered superior ergonomically compared to the other steering input devices evaluated. However, all evaluated steering input devices exceeded muscle activity and/or joint angle recommendations.Relevance to the industry: Compared to steering wheels, joystick steering showed reduced muscular activity and less awkward joint postures, suggesting a reduced risk of developing musculoskeletal disorders in the long term. However, the results warrant efforts to further develop joystick steering resulting in a reduction of exposure level beyond the existing solutions.

Global strategy of grinding wheel performance evaluation applied to grinding of superalloys

For grinding of superalloys, Difficult to Grind (DTG) materials, superabrasive grinding wheels of cBN (cubic boron nitride) with vitrified bond are considered the first choice for light roughing and finishing due to their superior performance when compared to conventional grinding wheels. However, there are limitations on the use of cBN wheels due to the higher initial cost of the cutting tool and the need for dressing systems with rotary tools. Aiming at reducing operational costs, the use of conventional grinding wheels with ceramic grains and high retention binder and lower bond-abrasive ratio is becoming increasingly common. In this scenario of introduction of new abrasive tools, it is necessary to use tools to evaluate the comparative performance of grinding wheels, which can encompass different aspects of the grinding process under study and which includes technical requirements of the component to be ground, as well as indicators of sustainability of the process. Thus, the objective of this work is to propose an evaluate strategy of the performance of grinding wheels whose methodology of analysis encompasses, in a coordinated way, traditional evaluation parameters and sustainability criteria (economic, environmental, and social) and that can be applied, as a study of case, in the grinding of superalloys for engine components, with different degrees of grindability. A high-performance engineered conventional grinding wheel and a vitrified cBN wheel were comparatively evaluated. The proposed methodology included the determination of the characteristic curve of a grinding wheel, coordinated analysis of the output parameters of the grinding process and the introduction of sustainability indicators. The results show the proposed global strategy proved to be viable and effective in comparing different grinding wheel specifications by encompassing aspects of the economic, environmental, and social performance of the grinding process. As a conclusion, the feasibility of the high-performance conventional wheel in substitution of the cBN wheel was confirmed for the grinding of the tested superalloys.

Evaluation of active Drivesticks as alternative controls in a high fidelity driving simulator

The developments in Steer-by-Wire Systems allow for the re-thinking of the commonly known steering system meaning both the development of new controls replacing the steering wheel as well as the design of the feedback corresponding to inform the human driver about the vehicle state. By conducting a user study in a high fidelity driving simulator this paper investigates the quality of vehicle stabilization performed via Active Drivesticks as alternative controls in comparison to the conventional steering wheel in a high-speed scenario. On a subjective level, assessed driving pleasure, experienced comfort and usability were high. Still, the subjective evaluation of safety feeling, experienced stress as well as necessary effort, was in favor of the conventional steering wheel, which subjects have been using over many years of driving. In addition, objective driving state variables that were measured to assess the participants’ performance in controlling the target path show a slight advantage for the classical steering control. In conclusion, it could be shown that despite the difference in experience and training with the different controls, the vehicle stabilization performed via Drivesticks is almost as good as the one performed via the conventional steering wheel in a high-speed driving scenario.

Design and validation of a kinematic numerical dressing model of conventional grinding wheels

Dressing is one of the most critical parameters that determine the efficiency of subsequent grinding processes. In this study, the analysis and validation of a kinematic dressing model for the case of corundum wheels is done. The accuracy of the model is evaluated by predicting the abrasive surface after the dressing operation for the case of a single-point dresser, observing the deviations between simulations and experimental results. These results show deviations of 19.2%, 7.57% and 19.69% for the roughness parameters root mean square height (Sq), density of peaks (Spd), and reduced peak height (Spk) respectively, which are indicators of the cutting ability of the grinding wheel and have influence on subsequent grinding processes in terms of the surface finish on the ground parts. These results show the way of future research work, giving useful information for optimising this numerical model and extending the analysis for different types of dressing tools.

Development of Niobium Microalloyed Steel for Railway Wheel with Pearlitic Bainitic Microstructure

Heavy haul transportation (load over 30 tons/axle), as well as the axle load, has been more and more used in Brazil and worldwide. The stress generated in the wheel-rail contact with loads up to 30 tons/axle is around 760 MPa, which causes premature wear and cracks of conventional wheels (AAR (Association of American Railroads) class C). Microalloyed wheels are fundamental on heavy haul transport, whose main function is to combine high hardness, ductility, and yield strength of the material in order to prevent shelling. The main purpose of this research is to develop a new microalloyed wheel steel with niobium addition that meets all the requirements of the AAR class D material with mixed microstructure composed of pearlite and bainite. The 0.71C/0.020Nb steel developed in this study (Nb material) for railroad achieved the standards required for AAR class D in all mechanical properties, with fracture toughness higher than the usual vanadium microalloyed steel used in comparison. The Continuous Cooling Transformation (CCT) diagram showed the presence of bainite even at very low cooling rate, in the range between 0.3 - 2 °C/s. These cooling rates to form bainite are much lower than those observed in other steels with similar composition.

A Four-legged Robot’s Soft Feet Structural Design and Walking Gait Generated from Inverse Kinematics

The conventional wheel is famous in the industrial mobile robot because it is simple to build and easy to control and to maneuver. On the other hand, the legged robot is complicated to control but has a high performance in locomotion like highly evolved legged-creatures. This research describes the four-legged robot design platform with the soft feet, which are made by silicone-material forming. The robot’s feet are implanted by the strain gauge sensor. The robot can percept the external force sensitively when its feet touch something. The research demonstrates the forward kinematics and inverse kinematics of a four-legged robot with three joints for each. The result has validated the kinematic equations by implementing them on the real dog-like pet robot. The robot walked with a pure walking gait and showed a sensing signal from the soft foot and ground contact.

Effect of different grinding fluids applied in minimum quantity cooling-lubrication mode on surface integrity in cBN grinding of Inconel 718

Inconel 718 (IN 718) is one of the important nickel based alloys that is being extensively used in aerospace industry. Being an aerospace material, surface integrity is of paramount importance due to high risk factor involved in this kind of industry. Superabrasive grinding wheels are believed to be superior over conventional wheels, which can improve the surface integrity of the ground component. Further, minimum quantity cooling lubrication (MQCL) is seems to be a promising technique that can also yield desirable surface quality. Therefore, in the present study IN 718 was ground with single layer superabrasive cBN wheel with neat oil, soluble oil water emulsion and different nanofluids in MQCL mode, and the surface integrity was studied. Flood cooling was also used as a benchmark. Residual stress, ground surface morphology, and surface roughness were studied using X-ray diffraction, scanning electron microscope, and 3D surface profilometer, respectively. Chip morphology was also studied using scanning electron microscope to correlate it with the surface quality of the job. Performance of MQCL neat oil was found to be the best as compared to other fluids in the context of surface integrity due to proper lubrication and grit penetration.

A Study on the Punch Shape for Improving Tool Life in Shearing AHSS

The adoption of hot rolled AHSS(Advanced High-Strength Steel) has been increased in accordance with the weight reduction of the chassis. The problem of tool life in punching the hole for high-strength steels is more important. Using the high-grade die material is one of the method to improve tool life. Another method for increasing the tool life is reducing the maximum punching load. We investigated the effect of tool shape on reducing the punching load. Conventional, shear-angled and humped tool geometry are considered for punching the flat sheets with 780MPa strength. In flat sheet, the maximum punching load is compared for each case of puch types. Maximum punching load is reduced by 40% of conventional punching process. For investigating the effect of punch shape in a real part, the punching process for the vent hole of the conventional wheel disc is modeled with FEM. The maximum load is efficeintly reduced by using the shear-angled punch.

A Novel Omnidirectional Mobile Robot With Wheels Connected by Passive Sliding Joints

Mobile robots for automatically transporting products in factories and warehouses contribute to an increase in efficiency. Omnidirectional mobile robots can move immediately in an arbitrary direction and overcome the disadvantages of lack of mobility in conventional mobile robots. However, the omnidirectional mobile robots proposed in the past have not been as reliable as the conventional mobile robots, such as automated guided vehicles (AGVs) due to their complicated wheel mechanisms. This paper proposes a novel omnidirectional mobile robot named slidable-wheeled omnidirectional mobile robot (SWOM), which has three wheels that connect to the robot body by three passive sliding joints. The relative movements of the sliding joints allow SWOM to use conventional wheels. Thus, SWOM realizes both omnidirectional mobility and structural reliability. In this paper, we discuss the kinematic conditions for omnidirectional mobile robots and prove theoretically that SWOM can achieve omnidirectional movement. We present a kinematic analysis, a reachable region evaluation considering the limited movable range of the sliding joints, and trajectory generation that enables SWOM to move unlimitedly. We develop a prototype of SWOM and conduct experiments that show SWOM actually moves according to the theory. From above, we verify the effectiveness of SWOM as an omnidirectional mobile robot.

High speed moderate depth grinding of Ti-6Al-4V using monolayer cBN wheel

Investigations on the grindability of titanium alloy with conventional wheel were mostly limited to a wheel speed of 30 m/s. Even with the monolayer electroplated cBN wheel, most of the experiments were limited to a wheel speed of 30 m/s. Surface residual stress which is the most important aspect of surface integrity of ground surface has also rarely been studied for titanium alloy. In the present work, the grindability of widely used titanium alloy, Ti-6Al-4V has been experimentally investigated in high speed grinding mode at a wheel speed of 90 m/s. Specific grinding energy was observed to be in the range of 160–200 J/mm3, which is much higher than the same observed while grinding ferrous alloys. For ferrous alloys, it is mostly limited within 100 J/mm3. No sign of wheel loading, grit pullout or grit tip adhesion of the chip was observed. Surface residual stress was found to be compressive in nature and become more compressive with increase in downfeed. However, surface residual stress was found to be highly tensile in the range of 300–500 MPa while using conventional SiC wheel.

Computational analysis of air jet wheel deflector for aerodynamic drag reduction of road vehicle

A concept of an air jet wheel deflector is employed to reduce vehicle aerodynamic drag. The drag reduction mechanism of the air jet wheel deflector is as follow: When the vehicle’s driving speed is over than predetermined value, the air jet system injects air in the perpendicular direction to the free stream flow. This air jet acts as an air curtain, which reduces the aerodynamic drag by deflecting the free stream flow away from the tire. Feasibility study was performed using state of the art computational fluid dynamics (CFD) technique based on the lattice Boltzmann method. Fabijanic’s simple vehicle model is used for the validation of current CFD technique and numerical study of both the conventional wheel deflector and newly proposed air jet wheel deflector. Parametric studies reveal that the air jet wheel deflector system effectually reduces vehicle aerodynamic drag up to 6.4%, while conventional wheel deflector leads to slight diminishment of aerodynamic drag of 3.6%. From this finding, it can be concluded that air jet wheel deflector is a useful device to reduce aerodynamic drag of automobile.

Viability of Hydro Kinetic Turbine as an Alternative for Renewable Energy Harvesting in Nigeria

The rationale behind this research is the development of a zero-head floating system using a conventional hydrokinetic water wheel as a model to examine and determine its performance in an open channel condition for energy harvesting in Nigeria. The power is determined by flow of water in the stream which is responsible for rotating the blades. The research entails the water flow driven by a pump at 0.4[m/s] and 0.6[m/s] water velocities around a pool. The turbine is made to float under this free stream velocity. Feasibility study of its viability in Gari dam in Kano state of Nigeria was carried out and an average flow and discharge were determined during the dry season. Findings of this research were quite impressive and can be used to design a suitable floating zero-head turbine for energy harvesting in Nigerian rural areas where the head is low and energy is required not only for mechanization but also for lighting and irrigation purpose.

Modified wheel tracker as a potential replacement for the current conventional wheel trackers

This research introduces a modified method for the wheel tracker test. Conventionally, the test is conducted by placing asphalt slabs or cylindrical cores in a fully confined steel or polyethylene moulds. The research work undertaken by the author has shown that having the specimen fully confined in all directions by the steel or polyethylene mould would limit or prevent it from lateral (shear) deformation. It is also well-known that shear related permanent deformation is identified as the primary cause for high severity rutting. As a result, a new wheel tracker test set-up was designed and manufactured to capture the true material response under the applied load. In the conventional wheel tracker, the large majority of samples will only show the primary stage and very small part of the secondary stage of the permanent deformation curve and most of the time the curve will plateau regardless of the number of cycles applied. Therefore, in the conventional wheel tracker test, the tertiary stage never reached in the vast majority of the tested specimens. In the modified wheel tracker, the three stages of permanent deformations are always captured; therefore, the flow number can be determined. In addition, the effect of the major mix parameters and test conditions such as air voids content, aggregate gradation, binder type and test temperature can be captured and analysed.

A New Localization System for Indoor Service Robots in Low Luminance and Slippery Indoor Environment Using Afocal Optical Flow Sensor Based Sensor Fusion.

In this paper, a new localization system utilizing afocal optical flow sensor (AOFS) based sensor fusion for indoor service robots in low luminance and slippery environment is proposed, where conventional localization systems do not perform well. To accurately estimate the moving distance of a robot in a slippery environment, the robot was equipped with an AOFS along with two conventional wheel encoders. To estimate the orientation of the robot, we adopted a forward-viewing mono-camera and a gyroscope. In a very low luminance environment, it is hard to conduct conventional feature extraction and matching for localization. Instead, the interior space structure from an image and robot orientation was assessed. To enhance the appearance of image boundary, rolling guidance filter was applied after the histogram equalization. The proposed system was developed to be operable on a low-cost processor and implemented on a consumer robot. Experiments were conducted in low illumination condition of 0.1 lx and carpeted environment. The robot moved for 20 times in a 1.5 × 2.0 m square trajectory. When only wheel encoders and a gyroscope were used for robot localization, the maximum position error was 10.3 m and the maximum orientation error was 15.4°. Using the proposed system, the maximum position error and orientation error were found as 0.8 m and within 1.0°, respectively.

Grinding temperature and power consumption in high speed grinding of Inconel 718 nickel-based superalloy with a vitrified CBN wheel

As a kind of typical difficult-to-cut metallic material, Inconel 718 nickel-based superalloy has been widely applied in aero-engines. High speed grinding experiments of Inconel 718 have been carried out using a vitrified cubic boron nitride (CBN) superabrasive wheel in the current study. The effects of wheel speed vs on grinding temperature and power consumption were investigated. Meanwhile, the grinding performance was also analyzed from the viewpoint of undeformed chip thickness. The results obtained show that, the minimum grinding forces and specific grinding energy are obtained at vs of 120m/s and the grinding temperature is less than 100°C at this moment. The lost grinding power reaches the maximum value when vs is 140m/s, which accounts for about 55%–65% of the total grinding power; however, the minimum values, such as about 20%–30%, are obtained at a conventional wheel speed. Finally, the wheel speeds in grinding Inconel 718 are optimized at 100–120m/s under the given experimental conditions, with which not only the surface roughness Ra below 0.4μm is obtained, but also the distorted lattice or elongated grain cannot be formed in the ground surface/subsurface layer.

Model predictive controller-based multi-model control system for longitudinal stability of distributed drive electric vehicle

Distributed drive electric vehicle(DDEV) has been widely researched recently, its longitudinal stability is a very important research topic. Conventional wheel slip ratio control strategies are usually designed for one special operating mode and the optimal performance cannot be obtained as DDEV works under various operating modes. In this paper, a novel model predictive controller-based multi-model control system (MPC-MMCS) is proposed to solve the longitudinal stability problem of DDEV. Firstly, the operation state of DDEV is summarized as three kinds of typical operating modes. A submodel set is established to accurately represent the state value of the corresponding operating mode. Secondly, the matching degree between the state of actual DDEV and each submodel is analyzed. The matching degree is expressed as the weight coefficient and calculated by a modified recursive Bayes theorem. Thirdly, a nonlinear MPC is designed to achieve the optimal wheel slip ratio for each submodel. The optimal design of MPC is realized by parallel chaos optimization algorithm(PCOA)with computational accuracy and efficiency. Finally, the control output of MPC-MMCS is computed by the weighted output of each MPC to achieve smooth switching between operating modes. The proposed MPC-MMCS is evaluated on eight degrees of freedom(8DOF)DDEV model simulation platform and simulation results of different condition show the benefits of the proposed control system.