Estimation of operational intention and personal adaptation in power assist system

• Main Author: Mohd Hazwan, Abd Latif
• Format: Thesis
• Language: English
• Published: 2013
• Subjects: TJ Mechanical engineering and machinery
• Online Access: http://umpir.ump.edu.my/id/eprint/9030/1/MOHD%20HAZWAN%20BIN%20ABD%20LATIF.PDF; http://umpir.ump.edu.my/id/eprint/9030/

In recent years, social problems of elderly society such as the decreasing number of careworkers and heavy work of nurses have been increased. Especially, transferring of bed in hospital requires two nurses and the task is heavy and difficult. Therefore, power assist system is one of the effective solution and it is possible to reduce the number of nurses for operation from two person to one. In this study, the power assist system is applied to an Omnidirectional Mobile Bed (OMB), which can move in any directions and less movement is required to change direction, very advantageous in narrow spaces. The goal of this study is to provide a nurse with power assist system that can help to move easily an OMB in narrow and crowded spaces in hospital. When the power assist system was installed to the OMB, there was a problem that the OMB did not move in the intended direction of the operator. Therefore, improvement of the operability was attempted by using direction reasoning by fuzzy reasoning. In this method, the rules are designed by how the force is applied by the operator, and the operation of the OMB is determined by the fuzzy ruled and fuzzy parameters. However, when the operator is changed, it is necessary to tune the fuzzy parameters according to operator's parameters characteristics. As the tuning by trial and error takes along time, in this paper, the fuzzy parameters are automatically tuned by using a neuro-fuzzy system ANFIS (Adaptive-Network-Based Fuzzy Inference System). The fuzzy parameters are auto-tuned by ANFIS by using teaching signals and input of the operator. The teaching signal is the data of the operator ' s intended direction of movement. The simulation results shows that there are improvement of operability of power assist after the tuning process for three opearators. Finally, the effectiveness of the proposal approach is demonstrated through experiments.