• Proceedings of the ESK Conference
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• 1997.04a
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• pp.145-149
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• 1997

General joystick using spring only has a vibration when operaor drops the joystick. If it is used as input of motorized wheelchair, its system have a serious problem which operator fall into dangerous situation. Therefore, In this paper proposed non-vibration joustick which control a motorized wheelchair. Non-vibration joystick was designed which return to origin point when operator drops joystick by mistake. Reflected force of non- vibration joystick is defined as addition displacement and variation rate. And each parameter has elasticity of spring and viscosity of DC servo motor. Through simulation for virtual environment, we found two coefficient to return origin point smoothly when a disabled person drops the joystick. In case of larger elastic coefficient of spring than viscous coefficient, we confirmed the result has the equal vibration of general joystick (under-damping). In opposite case, joystick returned to origin point with excessive force. As a application of non-vibration joystick, we experimented wall-following controlling. In this trial, we corroborated that joystick follows smoothly around the corridors.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.4
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• pp.549-554
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• 2012

Noncontactable joystick for a low speed electric vehicle(LSEV) is developed. The joystick is proposed to replaced the steering wheel in a conventional LSEV. The main advantages of the proposed joystick are a durable and a stable in structure, simple and easy to control through discriminating the driving and braking area. To reduce error and stability in the joystick control, input and output signal of the joystick are manipulated by data averaging and differntiation. With this algorithm, the driving resolution and capability are improved. To verify the proposed algorithm, a simple prototype model which has two electric motors for propulsion and steering are used. Test results show that the prototype joystick control system is applicable to an LSEV dirve.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.12
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• pp.1207-1212
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• 2007

We propose a haptic interface algorithm for joystick operators working in remote control systems of unmanned vehicles. The haptic interface algorithm is implemented using a force-feedback joystick, which is equipped with low price DC motors without encoders. Generating specific amounts of forces on the joystick pole according to the distance between a remote controlled vehicle and obstacles, the haptic interface enables the operator to perceive the distance information by the sense of touch. For the case of no joystick operation or no obstacles in the working area, we propose an origin control algorithm, which positions the joystick pole at the origin. The origin control algorithm prevents the false movement of the remote vehicles and provides the operator with a realistic force resisting the joystick pole's movement. The experiment results obtained under various scenarios exemplify the validity of the proposed haptic interface algorithm and the origin control algorithm.

• Journal of Biomedical Engineering Research
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• v.18 no.4
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• pp.447-456
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• 1997

When the disabled is operating a rehabilitation assisting system with a joystick by himself, unlike in the case of a normal person, tremor with joystick control or instant miscontrol can often occur. If these misoperations should be directly relayed to the system, shaking or malfunction of the mobile rehabilitation assisting system might be the result. The safety of the disabled is of prime concern. To solve this problem, that is, to prevent the miscontrol of the disabled operator and avoid crashes into his or her surroundings, we propose the force-reflection locomotion algorithm with the joystick. This method uses ultrasonic sensors to measure the distance between the object and mobile robot. Based on the reception of sensory data, the necessary torque is applied via the joystick to the attatched motor. To confirm the effectiveness of the proposed method, the subjects on the reflected force by the dynamic characteristics of the joystick and the reflected force by the distance information are tested Even though there are some differences in human dexterity, we confirmed the fact that the information from the obstacles was relayed to the operator via the joystick and resulted in an improved operational performance and safety level with regard to those obstacles.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.4
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• pp.358-363
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• 2006

This paper demonstrates a new non-contact electronic joystick using single hall sensor which detects a horizontal vector of the magnetic field. Furthermore, in this paper, it is mathematically modeled that nonlinear characteristics between the output of hall sensor and the movement of joystick bar. The dynamic horizontal vector of magnetic flux is detected by the hall sensor while a permanent magnet is rotated with the joystick bar, which has two dimension detecting area. Using the nonlinear adjustment equations, the output signals of hall sensor have been linearized to give higher accuracy in the two dimension movement. Finally, through the real experiments, it is showed that the single hall sensor structure mechanism is superior to the dual sensor structure in sensing the two-dimensional motion without offset.

• Journal of Mechanical Science and Technology
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• v.17 no.10
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• pp.1399-1410
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• 2003

In this paper, we develop a joystick manual driving algorithm for an electric vehicle called Cycab. Cycab is developed as a public transportation vehicle, which can be driven either by a manual joystick or an automated driving mode. The vehicle uses six motors for driving four wheels, and front/rear steerings. Cycab utilizes one industrial PC with a real time Linux kernel and four Motorola MPC555 micro controllers, and a CAN network for the communication among the five processors. The developed algorithm consists of two automatic vehicle speed control algorithms for normal and emergency situations that override the driver's joystick command and an open loop torque distribution algorithm for the traction motors. In this study, the algorithm is developed using SynDEx, which is a system level CAD software dedicated to rapid prototyping and optimizing the implementation of real-time embedded applications on distributed architectures. The experimental results verify the usefulness of the two automatic vehicle control algorithms.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.479-479
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• 2000

Recently, IVS(Intelligent Vehicle Systems) or ITS(Intelligent Traffic Systems) are much concerned subjects of automotive industry. In this paper, we will introduce an Intelligent Online Driving System for a car. This system allows the driver to be able to drive the car just by operating an integrated joystick. The proposed driving system could be implemented into any car and the key point of the design is that the driver still can drive the car as normal without using the joystick. Our Intelligent Online Driving System includes the integrated joystick, steering wheel control system, brake and acceleration (B&A)pedals control system, and the central control computer system. Steering wheel and B&A pedals are controlled by AC servo-motors. The integrated joystick generates the desired positions and the embedded computer controls these two servomotors to track the commands given by joystick. The control method for two servo-motors is PID control.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.723-726
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• 1988

This paper is a study about the automatic control of wheelchairs. This is realized by joystick, and is simulated by voice signal recognition. The control system by joystick is designed as follows: joystick paddle is connected with a timer and this timer ouput is high only when the joystick is moved. A computer reads the duration of this high state, and ouputs motor control word decided from this value using look-up table. The control system by voice signal is designed as follows: partial autocorrelation coefficients are computed from A/D converted signals and these values are compared with referance patterns. From this, the motor control word is decided on by the neareast neighbor rule.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.212-213
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• 2013

This paper proposes the algorithm of torque distribution in the electric wheel-chair using 2D joystick for drive safety. For the accurate driving performance, the specific and precise torque distribution is required in both wheels depending on signals of X-Y axis that is generated from 2D joystick. The signals of X-Y axis from joystick are transformed into the propulsion force and the torque reference. And the torque reference can be generated through the dynamic model of wheel-chair. The optimal dynamic characteristics of the electric powered wheelchair can be obtained, by adjusting the sensitivity coefficients of propulsion force and torque reference, In addition, the system takes smooth and stable control characteristics due to continuous torque output at all directions of joystick. The several simulations verify the usefulness of the proposed algorithm about torque distribution.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.103-106
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• 1996

In this paper, we proposed the design and algorithm of force reflection joystick which control mobile robot as a rehabilitation assistance system. The disabled persons are poor at joystick control because of hand vibration and clumsiness in operating it. These problems bring tasks which concerned with operator's safety So there is required technique which prevent collision with wall or obstacles. One of these solution is force reflection joystick which disturb that robot is closed to the wall. To confirm this way, we experimented and simulated with force reflection joystick which attached torque controller.