Development and evaluation of demonstration information recording approach for wheelchair mounted robotic arm

To offer simple and convenient assistance for the elderly and disabled, researchers focus on programming by demonstration approach to improve the intelligence and adaptability of wheelchair mounted robotic arm assistive robot. But how to easily and quickly obtain the demonstration information is still an urgent problem to be solved. Based on the systematic analysis of the daily living tasks in need of robot assistance, this paper proposes the key-point-based programming by demonstration recording approach to quickly obtain the demonstration information and develops a specified demonstration interface to simplify the operation process. A corresponding evaluation approach is also proposed from the demonstration trajectories and demonstration process two aspects. Additionally, tasks of “holding water glass task”, “eating task”, and “opening door task” are carried out and experimental results, as well as comparative evaluations confirm the validity of the proposed approach with high efficiency. This study can not only offer a convenient and feasible way to obtain the demonstration information of daily living tasks, but also lay a good foundation for the assistive robot to learn relative motion skills, especially for the demonstrated dexterous manipulation skills, and semi-autonomously accomplish complex, multi-step tasks following the user’s instructions in the daily home environment.

Recent Advances on Human-Robot Interface of Wheelchair-Mounted Robotic Arm

Background: Wheelchair mounted robotic arm is a typical assistive robot, which is widely used to help the elders and the disabled to complete the activities of daily life. But limited by the restrictions of the users’ athletic ability and cognitive ability, how to flexibly manipulate such robot is still a problem in front of them. The human-computer interaction technology is the core technology of the robot. Its performance directly affects the user's acceptability, satisfaction and promotion of intelligent wheelchairs. Objective: The study aims to give a general summary of recent human-robot interface of wheelchair mounted robotic arm and introduce their respective characteristics. Methods: Based on various patents and research developments about the human-robot interface of the assistive robot at home and abroad, this paper puts forward the basic principle of designing the humanrobot interaction mode, divides the man-robot interface into two categories based on the perspective of user control robot arm, and describes in detail, the typical human-robot interface and its related characteristics contained in each classification. Results: The development trends of the human-robot interface in future are predicted, so as to provide some research reference for the related scientific researchers. Conclusion: Wheelchair mounted robotic arm has important practical significance. Further improvements are needed in the design of the human-robot interface. It can effectively improve the operation performance of the WMRA, and take full advantage of the user’s existing movement ability to meet the requirement of dominating the control process. Furthermore, these improvements in the human-robot interface will allow more and more users to accept the WMRA, manipulate the WMRA, and enjoy improvements in the quality of their life for these assistive robots.

Mechanical Design and Analysis of a Wheelchair Mounted Robotic Arm With Adaptable Gripper and Remote Actuation System

Majority of wheelchair users experience upper-body muscular weakness, resulting from neuromuscular diseases, which limit their ability to perform common activities of daily living. A Wheelchair Mounted Robotic Arm (WMRA) will assist these individuals to eat, drink, and move objects as needed. This paper presents the design of a new WMRA as well as the analysis of its function. The design is side-mounted onto either a normal or power wheelchair, and incorporates a slim profile to allow ease of passage through doorways and be otherwise unobtrusive. The arm is easily removable, with assistance, for storage or travel. The mechanical design utilizes a belt and pulley system for remote actuation of each joint, driven by DC Gearmotors located in the base of the arm. This helps to shift the weight closer to the wheelchair and to maintain the required speed, torque and inertia while actively driving each joint of the robot. The end-effector is a unique design, intended to have the adaptability to securely lift a large variety of objects. Grasping simulations were performed on several standard objects which might be encountered daily. Structural, kinematic and workspace analyses are conducted, and results confirm that the designed WMRA is rated to lift a 4 kg payload, while also having a reach of 1.3 meters long radius.