• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.552-557
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• 2009

In this paper, we propose hybrid navigation system, for obstacle detection and avoidance in Intelligent wheelchairs (IWs). To robustly detect obstacles and avoid them on various environments, hybrid navigation system combines both range-sensor and camera information. For this, 10 range-sensors (2 ultrasonic and 8 infra-red sensors) and CCD camera are used. Through processing the informations obtained from those sensors, our system can detect obstacles with various sizes and shapes, and then avoid them. To assess the effectiveness of the proposed hybrid navigation system, it was tested on complex environments including various obstacles, then the results showed the potential of our system as mobility aids for disabled people.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.12
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• pp.1067-1076
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• 2016

This paper describes the development of a hybrid-powered wheelchair (HPW) for the elderly. The proposed HPW has novel mechanical and control features compared with conventional powered wheelchairs. An ergonomic back-braking mechanism was designed in order to stop the wheels easily. In terms of control features, the HPW remarkably reduces the muscle power required by combining various assistive functions, such as wheel torque assistance, friction/inertia compensation, gravity compensation, and the one-hand driving algorithm. For wheel torque assistance, strain gauges were attached to the hand-rim in order to measure the wheel torque applied by a human. Gyroscopes and an accelerometer were attached to the wheel and chair respectively for friction and inertia compensation. An inclinometer was attached for gravity compensation and the one-hand driving algorithm was included for patients who can only use one hand. The one-hand driving algorithm controls the angular velocity of the uncontrolled wheel by using a gyroscope and pressure sensors attached to the bottom of the seat. Finally, the performance of the proposed motion assisted algorithm was verified through various experiments.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.62-63
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• 2017

본 논문에서는 휠체어의 탑승자의 구동력과 BLDCM(Brushless DC Motor) 에서 출력되는 보조력인 전기적인 구동력을 동시에 사용하는 탈부착형 하이브리드 휠체어의 동작제어방식을 제안한다. 기존에는 휠체어에 토크센서를 부착하여, 토크센서 신호의 피이드백을 통하여 보조력을 발생하는 방식이 적용되고 있지만, 제안된 방식에서는 토크센서의 사용없이 사용자의 동작을 간접적으로 검출하는 방식을 제안한다. 사용자가 휠체어의 핸드림을 조작할 때, 발생하는 휠체어의 동작을 3축 가속도 센서를 통해 모션을 예측하고, 이에 대응하는 구동력을 보조하는 PAS(Power Assist System)을 설계하였다. 사용자의 동작 예측을 위해, 3축 가속도 센서의 신호를 조합하여 전진과 후진 및 정지 상태 신호를 예측하는 방식을 시뮬레이션과 실험을 통해 증명하였다.