Ball Wheel Research Articles

Fuzzy fractional-order adaptive robust feedback linearization control optimized by the multi-objective artificial hummingbird algorithm for a nonlinear ball–wheel system

Fuzzy fractional-order adaptive robust feedback linearization control optimized by the multi-objective artificial hummingbird algorithm for a nonlinear ball–wheel system

A Fuzzy LQR PID Control for a Two-Legged Wheel Robot with Uncertainties and Variant Height

This paper proposes a fuzzy LQR PID control for a two-legged wheeled balancing robot for keeping stability against uncertainties and variant heights. The proposed control includes the fuzzy supervisor, LQR, PID, and two calibrations. The fuzzy LQR is conducted to control the stability and motion of the robot while its posture changes with respect to time. The fuzzy supervisor is used to adjust the LQR control according to the robotic height. It consists of one input and one output. The input and output have three membership functions, respectively, to three postures of the robot. The PID control is used to control the posture of the robot. The first calibration is used to compensate for the bias value of the tilting angle when the robot changes its posture. The second calibration is applied to compute the robotic height according to the hip angle. In order to verify the effectiveness of the proposed control, a practical robot with the variant height is constructed, and the proposed control is embedded in the control board. Finally, two experiments are also conducted to verify the balancing and moving ability of the robot with the variant posture.

Design of Ball Wheel Vehicles With Full Mobility, Invariant Kinematics and Dynamics and Anti-Slip Control

Design of Ball Wheel Vehicles With Full Mobility, Invariant Kinematics and Dynamics and Anti-Slip Control

Controllers comparison to balancing and trajectory tracking a two wheeled mobile robot

This paper presents an optimal controller design using three different algorithms for trajectory tracking of Two Wheeled Balancing Mobile Robot TWBMR All the proposed algorithms have been investigated through simulations under the influence of different inputs tracking and exogenous disturbance This attempts to validate the significance of these algorithms in balance regulation and tracking trajectory These algorithms are represented by PID PID based parallel dual feed back serial dual feed back and hybrid optimal control using Feed forward PID and Feed back LQR Simulation results are provided to demonstrate that the hybrid controller can achieve a better robust performance in comparing to the other two design algorithms The graphical user interface GUI software has been used to show the simulation results in more convenient way

ATTITUDE CONTROL OF TWO WHEELED SELF-BALANCING VEHICLE

This paper mainly introduces the STM32 as the development platform of the two wheeled balancing car, and successfully developed a car model. Firstly, the paper studies the overall design scheme and the basic working principle of the car system. Secondly, the control flow of the software system of the two wheeled balancing car is deeply studied, and the double closed loop control of DC motor speed position is adopted to realize the normal operation of the car. Then, in the process of debugging, the three parameters of the virtual decomposition of the car system (the vertical ring, the speed loop, the steering ring) were tested respectively. In the end, the prototype of the two wheeled balancing car is debugged, and the running test is carried out for the obstacle free and the obstacles. The experimental results show that the two wheeled balancing car can be operated stably, and can realize the basic function.

Balancing and Trajectory Tracking of Two-Wheeled Mobile Robot Using Backstepping Sliding Mode Control: Design and Experiments

The key attributes of Two Wheeled Balancing Mobile Robots (TWBMRs) are nonholonomic constraints and inherent instability. This paper deals with the problem of balancing and trajectory tracking of TWBMR using backstepping Sliding Mode Controller (SMC). First, the mathematical representation of TWBMR is derived using Lagrangian method by incorporating the dynamics of DC motors. Then, a decoupling approach is applied for simplifying the dynamic equations. The backstepping SMC technique is finally adopted to achieve the balancing and trajectory tracking of the TWBMR, whereas both model uncertainties and exogenous disturbance are taken into account in the controller design methodology. In order to determine the velocity, the trajectory tracking is achieved by the kinematic control, which is a common backstepping controller. For the velocity convergence of TWBMR to the generated desired value, two SMCs are designed, in which the motors voltage are directly controlled as the control laws. Simplicity in practical implementation and control law, ability to overcome uncertainties and appropriate performance are the main advantages of the proposed controller. The effectiveness of the proposed controller is verified through simulation and experimental results.

A Novel Walking-Aid for Paralytic Patients Caused due to Stroke

The aim of this project is to fabricate an economical walking aid for Paralytic patients caused due to a stroke. The Paralysis caused due to stroke is referred as Hemiplegia or Hemiparesis. In general these patients walk with the assistance of another person. The patient first moves his unaffected leg as the assistant holds him firmly to give him support. Then the assistant pushes the impaired leg of the patient with his own leg while supporting him with his hands. In this way walking is achieved for the hemiplegic patient. To eliminate human assistance, the patient can also use a wheel chair to move from one place to another, especially the Autonomous Robotic Wheelchairs (ARW) that are being used these days. However, in order to gain back his motor capabilities, he should promote the use of hemi paretic limb during functional tasks. Active participation is critical to the motor learning and recovery. So designing a mechanism which enables movements on paralyzed body is crucial for functioning of other parts of the body as this prevents blood stagnation due to continuous rest given to specific parts. A DC motor along with some pulleys are used for actuating the leg and a telescopic tripod wheeled balancing support is used for providing counter-torque that helps the person from falling down on paralyzed side.

Design and Testing of a 2-DOF Ball Drive

Omnidirectional mobile robots offer interesting features for industrial and service applications, in particular, when operating in tight spaces. Compared to car-like nonholonomic vehicles, they provide a higher degree of maneuverability, and often require less complex path planning and control schemes. Three different types of holonomic wheels that enable omnidirectional motion have been proposed in literature: universal, Mecanum, and ball wheel mechanisms. A problem commonly associated with the first two wheel types is that they induce vibrations in the system due to the discontinuous contact points. In this article, a ball wheel mechanism with superior features including slip measurement, free-wheel modus and attrition sensing is presented. The first prototype was built using additive manufacturing. The requirements for the design and possible improvements for future versions are discussed. Based on the presented ball wheel drive, a design for an omnidirectional mobile robot platform driven by three redundant ball wheel units is proposed. The velocity kinematic model of this mobile base is also addressed. Moreover, motion planning for an individual ball drive is demonstrated by means of an online trajectory generation scheme. The pseudocode of the trajectory planning algorithm implemented in LabVIEW is then presented. Finally, the motion characteristics of the ball drive mechanism are tested and its functionality is evaluated in detail. Measurements obtained from these tests show that the slip between the ball wheel and the ground can be estimated quite accurately. Hence, it is expected that these improved dead-reckoning estimates will result in a higher positioning accuracy of the final base.

観光施設利用を目指した球体駆動式全方向移動機構のメンテナンス性および静粛性向上の検討

観光施設利用を目指した球体駆動式全方向移動機構のメンテナンス性および静粛性向上の検討

球体駆動式全方向移動機構とロボカップサッカー中型ロボットリーグへの応用

球体駆動式全方向移動機構とロボカップサッカー中型ロボットリーグへの応用

Tennis Transmitter Design and Parameter Optimization

Design of tennis transmitter design parameters, structure design, choice of institution, etc., the transmitter in accordance with the standards of the international tennis federation (ITF) to carry on the design. Design and institutional selection includes the realization of the crank connecting rod mechanism and control motor sports, ball tray and ball under the control of the speed of tennis, crowded ball wheel speed regulating motor selection, crowded round ball structure design and checking calculation, the design and checking calculation of shaft, casing and bracket material design and the selection, selection of walking wheel, etc.

球体駆動式全方向移動機構を用いた歩行訓練ロボットの開発

本研究では，杖歩行の習得を効率的に支援する歩行訓練ロボットの開発を行う．ロボットは自走式とし，移動台車に訓練者の歩行の支えとなる支持部材が立設された杖型の形状とする．移動台車に全方向移動機構を用いることで，訓練者が意図する方向へ自在な移動が行える．ロボットは訓練者に対し訓練と介助の2つの要素を提供する．訓練要素では，ロボットが訓練者の歩行前方の床面に足の踏み出し位置を映像により投影する．ロボットはこの目標位置に対する訓練者の足の踏み出しが，適切であるか判断し，フィードバックを与える．介助要素では訓練者の歩行時のバランスを保ちながら，杖歩行のリズムや訓練のモチベーションを高めるような音声を出力する．このロボットを用いて訓練者が楽しみを持って訓練に臨め，さらに介助者の省力化が図れる歩行訓練システムの開発に着手する．

Collision-Detecting Device for Omnidirectional Electric Wheelchair

An electric wheelchair is the device to support the self-movement of the elderly and people with physical disabilities. In this paper, a prototype design of an electric wheelchair with a high level of mobility and safety is presented. The electric wheelchair has a high level of mobility by employing an omnidirectional mechanism. Large numbers of mechanisms have been developed to realize omnidirectional motion. However, they have various drawbacks such as a complicated mechanism and difficulty of employment for practical use. Although the ball wheel drive mechanism is simple, it realizes stable motion when negotiating a step, gap, or slope. The high level of mobility enhances the freedom of users while increasing the risk of collision with obstacles or walls. To prevent collisions with obstacles, some electric wheelchairs are equipped with infrared sensors, ultrasonic sensors, laser range finders, or machine vision. However, since these devices are expensive, it will be difficult for them to be widely used with electric wheelchairs. We have developed a prototype design of collision-detecting device with inexpensive sensors. This device detects the occurrence of collisions and can calculate the direction of the colliding object. A prototype has been developed to perform motion experiments and verify the accuracy of the device. The results of experiments are also presented in this paper.

Design and Modeling of a Ball Wheel Mobile Robot

A new generation for an omni-directional ball wheel mobile robot with unique driving mechanism is introduced. This driving system overcomes to problems arise using traditional omni-wheels such as, vibration, inappropriate to employ in outdoor applications and limited load capacity. Mechanical structure of this robot has several distinctive characteristics in comparison with our previous robot. Modularity of driving system is the most important ability of new robot, beside on appending a suspension system to improve behavior of robot in rough terrains. Due to independent operation of three ball wheel chassis, designed robot has high performance in going over obstacles along its path.

Holonomic Omnidirectional Vehicle with Ball Wheel Drive Mechanism

A holonomic omnidirectional vehicle can instantly produce speed in any direction. It has a high level of mobility even on narrow spaces and expected to have a wide field of application. A lot of mechanisms have been developed to realize omnidirectional motions. However, no vehicle achieves an optimal balance between mechanism and control. We have been developed a holonomic omnidirectional vehicle with ball wheel drive mechanism. This mechanism has three ball wheels and three actuators, in which each ball wheel is driven by two actuators. This mechanism do not cause over constraint, because the number of actuators agrees with the number of motion freedom on a flat surface. It was realized to devise layout of ball wheels and actuators. Also this mechanism is simple, but it can easily be controlled and has a high level of mobility. A prototype vehicle was developed to perform experiments of absolutely necessary performance in practical use. In motion experiments, we confirmed step overcoming, gap traversing and slope climbing ability on riding an adult (approximately 56 [kg] ).

Optimal Actuation for an Omnidirectional Mobile Platform with Three Ball Wheels

This paper presents a method for optimally actuating a novel omnidirectional wheeled mobile platform with three driven ball wheels. This platform, which will be integrated with a manipulator, is designed for use in unstructured and congested environments such as those of highway maintenance and construction work sites. The designed ball wheel mobile platform can move in all directions on the plane, instantaneously and isotropically. For accurate motion control with parametric uncertainty in the dynamic model, an adaptive controller is applied for trajectory tracking control of the three-ball wheel platform. Each ball wheel has two active drive mechanisms which makes the platform redundantly actuated for in-plane motion. As such, a pseudo-inverse method is used for redundancy resolution and optimal torque distribution. Simulation results demonstrate the effectiveness of the approach.

Motion of a Ball Wheel Based Omnidirectional Platform Over Uneven Terrain#

Recent work by the present authors has presented a redundant, reconfigurable ball wheel mechanism, and the motion of an associated omnidirectional platform was simulated on flat terrain (Lee et al., 2007). The outdoor environment usually contains uneven terrain, and in this article, motion of an omnidirectional-wheeled mobile platform based on three ball wheel drive mechanisms is studied when the platform moves on uneven terrain that is modeled as a smooth surface. A critical issue that arises for uneven terrain is that the point of contact of the wheel and the terrain is changing. This introduces three more degrees of freedom, which cannot be directly controlled and should also be considered in uneven terrain motion. Herein, Euler–Rodrigues parameters are used to derive the necessary transformations, and Montana's contact equations with the geometric parameters of the terrain are used for tracing the contact point. Simulation results are then presented for motion on flat terrain and both concave and convex spherically shaped terrain. The results clearly show the effectiveness of the proposed method, which can accommodate other more complex terrains provided that the surface configuration is given in an orthogonal coordinate chart.

球状車輪型全方向移動車輌のファジィ制御

In this paper, motion control for omni-directional vehicle with ball wheels is considered. The proposed omni-directional vehicle has two ball wheels, and the actuators are arranged to X-direction and Y-direction in ball wheel. Hence, omni-directional vehicle has the ability to move in arbitrary speed and direction, and has also the ability to turn around the place. The proposed control system consists of the fixed gain feedback controllers and self tuning fuzzy controllers. To achieve improvement of responses, rules of fuzzy controller are automatically adjusted by a tuning law. To achieve improvement of mobility, the optical mouse sensor is installed on omni-directional vehicle for self-localization. The experimental results demonstrate the effectiveness of the proposed system for improvement of the movement performance of the omni-directional vehicle.

Analysis and Experimental Verification of a Three-Dimensional Noncontacting Angular Motion Sensor

A three-dimensional noncontacting angular motion sensor, based on magnetometry, has been developed for velocity feedback in the ball wheel mechanism, which serves as the drivetrain for a class of omnidirectional mobile platforms. More generally, this scheme tracks rigid-body rotation about a fixed point with an undefined axis of rotation. The approach involves tracking the time-varying magnetic field of a permanent disc magnet embedded at the center of the sphere. This data is then used to determine the absolute orientation of the magnet axis. Finally, an approach based on the natural invariants of rigid-body motion is used to determine the instantaneous axis of rotation and the angular speed of the sphere about this axis. In this paper, the sensing scheme is formulated, effects of geometric offsets within the tri-axial fluxgate magnetometer are addressed, and results from experimental verification are presented.

Control of a redundant, reconfigurable ball wheel drive mechanism for an omnidirectional mobile platform

SUMMARYThis paper develops a controller for position tracking of a new ball wheel drive mechanism for a robust omnidirectional wheeled mobile platform, an adaptive controller with physical parameter estimation. This platform, integrated with a manipulator, is designed for use in highway maintenance and construction, which is a generally unstructured and congested environment. The proposed ball wheel mechanism can move in all directions on the plane, instantaneously and isotropically. Reconfiguration of the redundant drive system of the ball wheel mechanism is accomplished by altering the contact pressure between the drive wheels and the sphere based on platform heading direction. The system redundancy is resolved through a Weighted Optimal Torque Distribution method allowing for smooth reconfiguration. Finally, experimental and simulation results demonstrate the effectiveness of the approach.