Evaluation of effectiveness of a power-assisted wire suspension system compared to conventional machine

Advances in Human-Computer Interaction

2012

Power assist systems are usually used for rehabilitation, healthcare, and so forth.This paper puts emphasis on the use of power assist systems for object transfer and thus brings a novelty in the power-assist applications. However, the interactions between the systems and the human users are usually not satisfactory because human features are not included in the control design. In this paper, we present the development of a 1-DOF power assist system for horizontal transfer of objects. We included human features such as weight perception in the system dynamics and control. We then simulated the system using MATLAB/Simulink for transferring objects with it and (i) determined the optimum maneuverability conditions for object transfer, (ii) determined psychophysical relationships between actual and perceived weights, and (iii) analyzed load forces and motion features. We then used the findings to design a novel adaptive control scheme to improve the interactions between the user and the system. We implemented the novel control (simulated the system again using the novel control), the subjects evaluated the system, and the results showed that the novel control reduced the excessive load forces and accelerations and thus improved the human-system interactions in terms of maneuverability, safety, and so forth. Finally, we proposed to use the findings to develop power assist systems for manipulating heavy objects in industries that may improve interactions between the systems and the users.

Section: Advances In Human-computer Interactionmentioning

confidence: 99%

Improving Interactions between a Power-Assist Robot System and Its Human User in Horizontal Transfer of Objects Using a Novel Adaptive Control Method

Advances in Human-Computer Interaction

2012

“…In [1], we argued that power assist systems could be used to handle heavy objects in various industries. There are few models of power assist robots for objects manipulation [4], [5]. However, these models do not include human features such as human's weight perception in their controls and thus these models are not so human-friendly.…”

Section: Introductionmentioning

confidence: 99%

Distinctions in Weight Perception between Constrained and Unconstrained Lifting of Objects

Hayakawa

et al. 2011

AEF

Abstract. We made two objects (hollow metal cylinders) with identical appearance. One was called the constrained object; another was called the unconstrained object. Human subjects lifted the constrained and unconstrained objects separately for various experiment conditions. We compared human's weight perception between the two types of objects. Results showed that weight perception between constrained and unconstrained lifting was almost the same. In our previous research, we developed a power assist system for lifting objects and determined a psychophysical relationship between actual and perceived weights for the objects lifted with the system [1]. The perceived weights were 40% of actual weights. However, the objects lifted with the system were constrained objects (as they were tied to the force sensor) that might affect the accuracy of the relationship. The results of this paper confirm that the constraint does not affect weight perception too much, which reconfirms that the psychophysical relationship between actual and perceived weights derived in our previous research was correct [1].

“…However, suitable power assist devices for lowering heavy objects in industries are not so visible. Few models of power assist robots for objects manipulation are available [4], [5]. However, these models are not designed exclusively for lowering objects and almost all of them do not include human features such as human's heaviness perception in their controls and thus these models are not so human-friendly.…”

Section: Introductionmentioning

confidence: 99%

Lowering Objects with a Power Assist Robot: The Preliminary Study

Hayakawa

et al. 2011

AEF

Abstract. We developed a 1-DOF power assist robot to lower objects from higher position to lower position. Subjects lowered objects of different sizes with the robot and we analyzed heaviness perception, load force, motions (displacement, velocity, acceleration) etc. We determined a psychophysical relationship between actual heaviness and perceived heaviness for objects lowered with the robot system. We tried to identify some control parameters from the analytical results, and proposed them to be used to determine and develop an appropriate control scheme for power assist robots for lowering heavy objects in various industries. This paper reports the preliminary study results on this issue.