• Journal of the Korean Institute of Intelligent Systems
• /
• v.25 no.1
• /
• pp.1-6
• /
• 2015

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.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.12 no.2
• /
• pp.154-161
• /
• 2012

This article presents experimental studies of fuzzy logic application to control a two-wheel mobile robot(TWMR) system. The TWMR system is composed of two systems, an inverted pendulum system and a mobile robot system. Although linear controllers can stabilize the TWMR, fuzzy controllers are expected to have robustness to uncertainties so that the resulting performances are expected to be better. Nominal fuzzy rules are used to control balance and position of TWMR. Fuzzy logic is embedded on a DSP chip to control the TWMR. Balancing performances of the PID controller and the fuzzy controller under disturbances are compared through extensive experimental studies.

• Proceedings of the IEEK Conference
• /
• 2009.05a
• /
• pp.109-111
• /
• 2009

In this paper, we discuss how to design 2-wheeled mobile robot hard wares as reasonable and practical as possible. A segway type mobile robot consists of 2 wheels only, placed in parallel rather than horizon. 2-wheeled mobile robots make you overcome high cost and time consuming maintenance procedures of the robot by reducing the number of robot hardwares. The most challenging thing in a 2-wheeled mobile robot that has many more valid virtues than the traditional mobile robots is to make it balance itself whenever it stands still or goes forward. But balancing itself is not an easy matter and there are many researches and experiments on this issue. When researchers test theories on 2-wheeled mobile robots to improve its self balancing performance, they should consider how to design hard wares of that mobile robot. No matter how great those new theories are, if a testbed for those theories is not suitable, performance output would be poor and meaningless. In this point of view, to design a proper 2-wheeled mobile robot as a testbed is a very important issue with development of new theories. So we define 4 guide lines to design segway type mobile robots reasonably; about motor, battery, and MCU selection and shock-proof design with robust motor setting.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.16 no.3
• /
• pp.188-196
• /
• 2016

For the balancing control of a one-wheel mobile robot, CMG (Control Moment Gyro) can be used as a gyroscopic actuator. Balancing control has to be done in the roll angle direction by an induced gyroscopic motion. Since the dedicated CMG cannot produce the rolling motion of the body directly, the yawing motion with the help of the frictional reaction can be used. The dynamic uncertainties including the chattering of the control input, disturbances, and vibration during the flipping control of the high rotating flywheel, however, cause ill effect on the balancing performance and even lead to the instability of the system. Fuzzy compensation is introduced as an auxiliary control method to prevent the robot from the failure due to leaning aside of the flywheel. Simulation studies are conducted to see the feasibility of the proposed control method. In addition, experimental studies are conducted for the verification of the proposed control.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.1
• /
• pp.87-93
• /
• 2014

Conventional two-wheeled balancing robots are limited in terms of turning speed because they lack the lateral motion to compensate for the centrifugal force needed to stop rollover. In order to improve lateral stability, this paper suggests a two-wheeled balancing mobile platform equipped with a tilting mechanism to generate roll motions. In terms of static force analysis, it is shown that the two-body sliding type tilting method is more suitable for small-size mobile robots than the single-body type. For the mathematical modeling, the tilting-balancing platform is assumed as a 3D inverted pendulum and the four-degrees-of-freedom equation of motion is derived. In the velocity/posture control loop, the desired tilting angle is naturally determined according to the changes of forward velocity and steering yaw rate. The efficiency of the developed tilting type balancing mobile platform is validated through experimental results.

• Journal of Institute of Control, Robotics and Systems
• /
• v.21 no.4
• /
• pp.342-348
• /
• 2015

This paper presents a two-wheel balancing mobile robot with linear workspace extension structures. The two-wheel mobile robot has two linear motions at the waist and shoulder to have extended workspace. The linear motion of the waist and shoulder provides some structural advantages. A dynamic equation of the simplified robot system is derived. Simulation studies of the position control of the robot system are performed based on the dynamic equations. The dynamic relationship between a two-wheel mobile system and linear extension mechanism is observed by simulation studies.

• Journal of the Korean Society of Industry Convergence
• /
• v.18 no.2
• /
• pp.67-74
• /
• 2015

Two-wheeled driying mobild robots are precise controlled in terms of linear contol methods without considering the nonlinear dynamical characteristics. However, in the high maneuvering situations such as fast turn and abrupt start and stop, such neglected terms become dominant and heavy influence the overall driving performance. This study describes the nonlinear optimal control method to take advantage of the exact nonlinear dynamics of the balancing robot. Simulation results indicate that the optimal control outperforms in the respect of transient performance and required wheel torques. A design example is suggested for the state matrix that provides design flexibility in the control. It is shown that a well-planned state matrix by reflecting the physics of a balancing robot greatly conrtibutes to the driving performance and stability.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.20 no.4
• /
• pp.469-475
• /
• 2010

This paper presents controller design of a two wheeled mobile inverted pendulum robot for one man transportation vehicle. Since the overall mass is varying with different drivers, suitable controller gains are obtained through experimental studies. Variation of the center of gravity due to different masses also affects stable balancing control. Thus, the desired balancing angle si required to be modified with respect to different masses. To measure masses for different drivers, a weight scale is used and those data are used for balancing control through communication. The gain scheduling method of using data obtained from experimental studies allows the robot to have stable balancing performances.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.26 no.1
• /
• pp.144-149
• /
• 2017

There have been lots of interest on service and entertainment robots. To ensure that robots work in harmony with humans, their stability and compactness are some of the key issues. Obviously, robots with fewer wheels occupy a smaller floor area compared to those with more wheels. In addition, robots with fewer wheels, whose posture stabilities are maintained by feedback control, are stable even under larger accelerations and/or higher locations of the center of mass. To facilitate controller design, it is assumed that both pitch and roll dynamics are decoupled. The dynamic equations of motion for the proposed robot are derived from the Euler-Lagrange equation. To obtain the optimal balancing control law, linear quadratic regulator control methods are applied to the linearized dynamic equations. Simulation and experimental results verify the effectiveness and performance of the proposed balancing control algorithm for a single-wheeled mobile robot.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.26 no.1
• /
• pp.23-29
• /
• 2016

This paper presents balancing control of a two-wheel mobile robot (TWMR). TWMR is aimed to maintain balance while moving. Although TWMR can be controlled by linear controllers such as PD controller, time-delayed controller is employed for robustness. Performances of PD controllers and time-delayed controllers are compared. Especially, experimental studies on different acceleration estimation for the time-delayed controller are conducted. Performances by different acceleration estimations of the balancing angle, of the position, and of both angle and position are compared empirically.