As the world enters an aging and super-aged society, the application of advanced technology in assistive devices to support the daily life of the elderly is becoming a hot issue. Among them, electric wheelchairs are representative assistive devices for the walking support of the elderly, and their structural form is similar to AGV and AMR. For this reason, research is being introduced and underway to guarantee the right to voluntarily move or improve the convenience of movement for the elderly and severely disabled people who have difficulties in operating a joystick for operating an electric wheelchair. Autonomous driving of mobile robots is a technology that configures prior information on the driving environment as a map DB and operates based on it. However, active driving assistance technology is needed because wheelchairs do not move in a limited space, but can move to a place without a prior map DB or vehicle boarding depending on the passenger’s intention to move. Therefore, a system for estimating the moving position and direction of the wheelchair is needed to develop a driving assistance technology in the relevant driving environment. In order to solve the above problem, this study proposes a position and direction estimation algorithm suitable for active driving of a wheelchair based on a UWB sensor. This proposal is an algorithm for estimating the position and direction of the wheelchair through the fusion of UWB, IMU, and encoder sensors. In this proposal, it is difficult to design an active driving assistance system for wheelchairs due to low accuracy, obstacles, and errors due to signal strength in the position and direction estimation with UWB sensors alone. Therefore, this study proposes a wheelchair driving position and direction estimation system that fuses the dead recording information of a wheelchair and the UWB-based position estimation technique based on sensors applied in IMU and encoders. Applying quantitative verification to the proposed technique, the direction estimation accuracy of the wheelchair of about 15.3° and the position estimation error average of ±15 cm were confirmed, and it was verified that a driving guide for active driving was possible when the sensor system proposed in a mapless environment of the wheelchair was installed at a specific destination.

This study proposes a following method based on ultrasonic sensors in consideration of the situation that requires collaboration while performing autonomous driving-based service robot tasks. Since it is impossible to follow the target when it is outside the transmission and reception range of ultrasonic sensors, this study proposes a method of extending the range by changing the angle of the ultrasonic sensor. It was confirmed that the proposed method can extend the transmission and reception range in comparing the transmission and reception range with the basic sensor installation method in which ultrasonic sensors are installed facing the front with each other.

Intelligent transfemoral prostheses, which have recently been studied, are equipped with a microcontroller, providing appropriate motion functions for their walking environments. Thus, studies have been conducted to estimate user intentions in locomotion movements by applying biomechanical sensors inside the socket. Among them, a pressure sensor is used to determine the intentions of locomotion movements through changes in the internal pressure of the prosthetic socket. However, existing studies have a problem in that the reproducibility of pressure change data is degraded due to the non-detection and saturation of the pressure measurement value. Accordingly, this study proposes a fabrication method for a wide and flexible pressure sensor that can solve this problem and a method for the identification of user intentions in locomotion movements using it. The proposed system was fabricated with Velostat film, which has a smaller noise impact and can be fabricated in various sizes and shapes. The fabricated sensor was attached to four points inside the socket, confirming the possibility of detecting the intention of six movements according to the multi-critical detection method. The proposed pressure-sensor-based intention detection system can be applied individually by prosthetic users through simple tasks. Moreover, it will be universally applicable for commercialization.

This study proposes a LiDAR-sensor-based elevator recognition technique to prevent collisions caused by poor operation and the cognitive decline of wheelchair users with upper limb disabilities. Existing elevator recognition studies show high performance for elevator door recognition, but this can only be recognized at a position where the elevator can be viewed directly due to the angle of view range of the sensor. This is not appropriate for wheelchair users who are inexperienced in operation because alignment must be performed directly based on the elevator. Therefore, this study presents a LiDAR-sensor-based elevator recognition technique that can detect elevators from the side to the position and at an angle to the front in order to solve this problem. In addition, this study proposes a technique for recognizing elevator gates finished with low- and high-reflective materials in order to enable recognition in various elevator environments. In order to quantitatively verify the elevator recognition technique proposed in this study, experiments were conducted in an elevator environment consisting of low and high reflections. The results of the experiments confirmed that there was no problem in applying the wheelchair active driving technique.