Single-wheel Robot Research Articles

Investigation of locomotion validity of a vertical wall climbing single-wheel robot for curved surfaces

Investigation of locomotion validity of a vertical wall climbing single-wheel robot for curved surfaces

Advanced Proportional-Integral-Derivative Control Compensation Based on a Grey Estimated Model in Dynamic Balance of Single-Wheeled Robot

This paper aims to design a one-wheeled robot as regards its pitch freedom and balance control on the one hand and to assess the application feasibility of the GM (1,1) swing estimation controller on the other. System control focuses mainly on one-wheeled robot stability, body swings in position, and speed control. Mathematical modeling and GM (1,1) prediction control are under investigation. The mathematical modeling is firstly conducted through referencing to the Newtonian mechanics and the Lagrange equation, from which the robot transfer function and state-space differential equation are derived. Next, the linear quadratic regulator is applied as the control rule at the balance point. Applying GM (1,1) to assess the robot gyro signal at a dynamic state is a discussion. Next, model reference estimation control is processed, and a mathematical model of the balance control method is completed. Finally, a simulation is conducted to verify the feasibility of the GM (1,1) estimation reference model. The linear quadratic regulator, which is credited with tenacity, can provide pitch swing and balance control of the one-wheeled robot.

Development of a single-wheeled inverted pendulum robot capable of climbing stairs

ABSTRACTIn this paper, we propose the design of a single-wheeled robot capable of climbing stairs. The robot is equipped with the proposed climbing mechanism, which enables it to climb stairs. The mechanism has an extremely simple structure, comprised of a parallel arm, belt, harmonic drive, and pulley. The proposed climbing mechanism has the advantage of not requiring an additional actuator because it can be driven by using a single actuator that drives the wheel. The robot is equipped with a control moment gyroscope to control the stability in a lateral direction. Experimental results demonstrate that the robot can climb stairs with a riser height of 12–13 cm and a tread depth of 39 cm at an approximate rate of 2 to 3 s for each step.

Development of a single actuator wheel robot with mechanical scalability and flexibility

Development of a single actuator wheel robot with mechanical scalability and flexibility

Introducing GyroSym: a single-wheel robot

In this paper, GyroSym, a compact highly-stable single-wheel robot is introduced. Symmetrical flywheels have been used as its stabilization mechanism to keep the wheel upright. Thanks to the type of the flywheel used, the dynamic equations of the robot is simplified, the torque needed to tilt the spin axis is reduced, and the space is drastically minimized. Besides, a centrifugal clutch is used to smooth the motion of the robot in forward motion. Two controllers, fuzzy and fuzzy-Pade, were implemented based on their ability to stabilize the robot. Although both prevented the GyroSym from falling over, neither can entirely cancel out the effects of nonlinear behaviors that is present in the response, represented as high-frequency low domain noise. However, fuzzy-Pade demonstrated more efficient functionality, response, and mathematical simplicity which made it a perfect choice for stabilizing the GyroSym. Experimental results of a prototype have validated that of the mathematical analysis and simulations.

Real-time Inverse Model Estimation by a Recursive Least Squares Method for Disturbance Observer-based Control Systems: Balancing Control of a Single-wheel Robot

This article proposes a real-time identification and control technique for disturbance observer (DOB) - based control systems to improve the balancing control performance of a single-wheel robot. In a DOB-based control configuration, the inverse model of the system is obtained by inverting the identified forward model to extract the disturbance. However, a problem arises when the stability of the inverse model is not guaranteed. The Q filter design may solve the problem, but the process is time consuming. Therefore, we propose a stable inverse model identification technique with a minimal effort of designing Q filters in DOB schemes. The proposed scheme follows three steps: a recursive least square (RLS) method is used for updating the parameters of a second order model. Then the stability is checked. The last step is to make the model stabilized depending upon the stability through the all-pass-filter technique. After these steps, the transformed inverse model becomes stable and finally can be used for DOB control schemes. Experimental studies on balancing control of a single-wheel robot are conducted and their performances are compared to verify the proposal.

Anti-Swing and Position Control of Single Wheeled Inverted Pendulum Robot (SWIPR)

This article presents a fuzzy logic based offline control strategy for the stabilisation of a single-wheeled inverted pendulum robot (SWIPR). A SWIPR comprises of robot chassis mounted on a single wheel. A Matlab-Simulink model of the system has been built from mathematical equations derived using Newton's second law of motion. The study considers three different shape membership functions (MFs) i.e. gaussian, gbell and trapezoidal for designing of fuzzy logic controllers (FLCs). The performance parameters considered for comparison of controllers were rising time, settling time, steady state error and maximum overshoot. The simulation results proved the superiority of gbell MFs over other MFs.

Object Recognition and Cooperative Pick-and-Place of a Single Spherical Wheeled Mobile Robot with Dual Arms

This paper presents techniques and methodologies for object recognition and cooperative pick-and-place of a single spherical wheeled mobile robot (SSWMR) with seven-degrees-of-freedom (7-DoF) dual arms. Both arms are cooperatively used to achieve a pick-and-place task by solving the inverse kinematics of both arms and performing on-line motion planning in real time. To maintain the SSWMR in a stable state to carry out the desired task, the robot is equipped with a lifting platform using four legs to support static stability. Image processing and pattern recognition methods are used to develop application programs based on the OpenCV and OpenNI library to recognize and locate desired objects to be grasped. Simulation and experimental results are used for successful illustration of the proposed techniques.

The Influence of the Swinging Arms on the Balanced Dynamics of a Wire-Walking Robot Running above a Flexible Wire

This paper focused on a single wheel robot that runs on a flexible wire, and the principal consideration was the influence of its swinging arms on the balanced dynamics of the system. The robot was designed with two swinging arms and a rotational pole to imitate a real human wire walker. Under the pure rolling condition of the single wheel, a dynamical model was developed for the system by Lagrange equation. With the model, balanced motions under the regulation of the rotational pole coorperating with the swinging arms were investigated. The inverse dynamics simulations showed that, the different swinging arms action would correspond to different driving input torques, but there would be a trough maximum torque at a certain feedback action of the swinging arms.

Awakening strategies from a sleeping mode to a balancing mode for a sphere robot

This paper presents the strategy of awakening a sphere robot from a sleep mode to a balancing mode. The sphere robot is designed on the basis of a single-wheel robot covered with two hemispheres to have the sphere shape with casters to maintain the sleep mode at a specific angle. The sleep angle has been empirically found to be 16 degrees for enabling the sphere robot to be upright position. The gyroscopic force is controlled to perform the awakening strategy of the robot system. Firstly, the key design features such as angular momentum, agility, and controllable bandwidth are investigated to identify three phases such as triggering, stumbling, and stabilizing for the awakening strategy. Secondly, the sphere robot is modeled as an inverted stick and the phase portrait of the model is analyzed. Thirdly, a control law with a compensation algorithm is proposed to enhance the stabilizing performance. Finally, the proposed awakening strategy is verified through experimental studies.

Detection and control of a gyroscopically induced vibration to improve the balance of a single-wheel robot

In this article, an experimental investigation of the detection of a gyroscopically induced vibration and the balancing control performance of a single-wheel robot is presented. The balance of the single-wheel robot was intended to be maintained by virtue of the gyroscopic effect induced from a highly rotating flywheel. Since the flywheel rotates at a high speed, an asymmetrical structure of a flywheel causes an irregular rotation and becomes one of the major vibration sources. A vibration was detected and suppressed a priori before applying control algorithms to the robot. Gyroscopically induced vibrations can empirically be detected with different rotational velocities. The detection of the balancing angle of the single-wheel robot was accomplished by using an attitude and heading reference system. After identifying the vibrating frequencies, a notch filter was designed to suppress the vibration at the typical frequencies identified through experiments. A digital filter was designed and implemented in a digital signal processor(DSP) along with the control scheme for the balance control performance. The performance of the proposed method was verified by the experimental studies on the balancing control of the single-wheel robot. Experimental results confirmed that the notch filter designed following the detection of the flywheel’s vibration actually improved the balancing control performance. A half of the vibration magnitude was reduced by the proposal.

외륜 이동로봇의 균형제어 알고리즘

외륜 이동로봇의 균형제어 알고리즘

외란관측기 설계를 위한 Q필터 시정수 영향 분석 : 외바퀴 로봇의 균형 제어 응용

고주파 유도가열장치는 LC공진회로에 고주파 전원을 인가하여 금속을 가열 할 수 있다. 공진회로는 워크 코일과 전도 냉각 커패시터로 구성되며, 커패시터의 특성에 따라 열처리 설비의 성능을 좌우한다. 그러나 전도 냉각 커패시터는 국내 원천기술의 연구개발 부족으로 해외 수입 의존도가 높다. LC공진 시 커패시터 내부의 발열을 최소화하고, 무효 전력손실을 줄이며, 내 전압특성이 우수한 커패시터가 요구된다. 국산화를 위하여, 선진 제조사의 완성품 커패시터의 주파수 응답 특성 분석에 대한 선행 연구가 필요하다. 주어진 로그-로그 특성 곡선의 임의 점에서 값을 읽기 위한 보간법을 연구하여 매틀랩 코딩으로 커패시터의 분석 도구로 적용하였다. 커패시터를 간단 화 된 RC 직렬 등가 회로로 가정하고, 등가 직렬 저항 ESL 값을 구하여 주파수 응답 특성 곡선을 재현하는 시뮬레이션을 시도하였다. 실제 무효전력의 피크 치에 대한 특성과 시뮬레이션 특성을 비교할 때 재현율이 83% 이상 결과 값으로 나타나는 것을 확인할 수 있었고, 이 알고리즘은 간단 화 된 모델의 커패시터 특성곡선을 분석하여 예측 할 때 적용이 가능하다.

Electromagnetic Force Balanced Single‐Wheel Robot

It is a challenging task to carry on the research concerning the lateral stabilization of Single wheel robot (SWR). The lateral dynamics of earlier flywheel stabilizing SWR is derived to explain the shortcomings of such a mechanism, and the recovery torque proportional to the acceleration and moment of inertia of the flywheel is proved. But as the motor being a speed server system, it is difficult to control its acceleration to actuate the flywheel to provide recovery torque for SWR; and the moment of inertia of the flywheel must be large enough to produce adequate recovery torque, which makes such a system rather cumbersome. We proposed a new mechanism to solve the problem by introducing an electromagnetic force. The proposed mechanism is described briefly, and the dynamic analyses of such a new SWR is given, then the stability analysis is also done. Three-dimensional (3D) multi-body simulation, numerical simulation and physical invented pendulum prototype experiments were conducted to verify the proposed mechanism. The experiment results verified that the proposed mechanism is feasible and have some advantages over the flywheel balanced SWR.

외바퀴 로봇의 역자이로 효과에 의한 바디 모션과 김벌 모션의 실험을 통한 관계 분석

Control Moment Gyro (CMG) has been used as an indirect actuator of a single-wheel robot system GYROBO, developed at Chungnam National University. The flip motion of the gimbal system produces the gyroscopic motion onto the body system while the body motion also produces the gyroscopic motion onto the gimbal system inversely. In this paper, the intuitive equation of the inverse gyroscopic effect is derived as the direct relation between the rate of the body system and the rate of the gimbal system. Experiments on the inverse gyroscopic effect under the chaotically generated disturbance are conducted. Experimental data are approximated by a linear equation using the least square method.

필터 설계를 통한 한 바퀴 구동 로봇의 진동 제어

In this paper, the vibration of a single-wheel mobile robot is minimized by designing a filter. An AHRS (Attitude and heading reference system) sensor is used for measuring the state of the robot. The measured signals are analyzed using the FFT method to investigate the fundamental vibrational frequency with respect to the flywheel's speed of the gimbal system. The IIR notch filter is then designed to suppress the vibration at the identified frequency. After simulating the performance of the designated filter using the measured sensor data through extensive experiments, the filter is actually implemented in a single-wheel mobile robot, GYROBO. Finally, the performance of the designed filter is confirmed by performing the balancing control task of the GYROBO system.

각도 오프셋의 퍼지보상을 통한 외바퀴 이동 로봇의 균형제어

In this paper, a fuzzy control method is used for balancing a single-wheel robot. A single-wheel robot controlled by the PD control method becomes easily unstable since the flywheel tends to lean against one direction. In the previous research, we have used the gain scheduling method. To remedy this problem, in this paper, a fuzzy compensation technique is proposed to compensate for the balancing angle. The fuzzy control method compensates offset values at the balancing angle to prevent the gimbal from falling against one direction. Experimental studies of the balancing control performance of a single-wheel mobile robot validate the proposed control method.

Development and control of a single-wheel robot: Practical Mechatronics approach

This article presents a Mechatronics approach to make the complex dynamical system satisfy the specification as desired. The Mechatronics approach has several phases: analytical design, system integration, sensing & control, and evaluation. The Mechatronics approach means that cycles of design, implementation, sensing, and control are repeated until the system satisfies the goal through evaluation. A single-wheel robot system called GYROBO after a robot that uses gyroscopic effect is developed and controlled by the Mechatronics approach. The goal of GYROBO is to navigate its terrain while maintaining the stable balance. However, successful balancing and navigation of a single-wheel robot are quite difficult and challenging since one point contact may fall down in lateral direction with ease. To have a successful balancing performance, many problems have to be solved a priori before applying any advanced control algorithms. Among several phases of analytical design, integration, sensing & control, and evaluation, the most important phase is the analytical design. However, the analytical design cannot guarantee successful performances due to the complexity of the system. Practical Mechatronic approach is to repeat cycles of system integration, sensing & control, and evaluation. After several modifications of mechanical assembly and relocation of components inside the wheel housing, simple linear controllers enable GYROBO to perform successful balancing and navigation. GYROBO is able to follow the specified trajectory given by a remote operator. Experimental studies of control of balancing, driving forward and backward, turning, and climbing over an obstacle of GYROBO are conducted to demonstrate and evaluate its functionality and support the concept of the Mechatronics approach to control complex systems.

A One Wheel Flying Robot

Recent advances in technology have lead to growing interest in robotic application. More recently, a growing interest in unmanned aerial vehicles (UAVs) has been shown among the research community. Being able to design a vertical takeoff and landing (VTOL)-UAV, which is highly maneuverable and extremely stable, is an important contribution in the field of aerial robotics since potential applications are tremendous (e.g., high buildings and monuments investigation, rescue missions, film making, etc.). For the navigation and military purpose their mainly two type of robot use: multi or single wheel robot and flying robot .But each type has certain limitation, to overcome from that here we have propose a novel concept of a robot called OWFR(one wheel flying robot) base on the Vertical takeoff and landing(VTOL) mechanism. OWFR can land on its single wheel .It can pass from a very narrow road as it has only one wheel. By simulation we have shown that it will efficiently land and fly in its single wheel and thus it is better than previous type of robots.

Dynamic Modeling of Single-Wheeled Robot

This paper presents a kind of single-wheeled robot (SWR, unicycle robot). Lagrange approach is used to formulate the dynamic model of the robot moving in 3 dimensions. The result of model simulation is consistent with the physical. The proposed dynamic model provides some theoretical basis for designing and controlling SWR.