A Parameter Estimation Method of Human Hand Skin-Electrode Bioimpedance Model Based on Electrotactile Device

Abstract

A method for parameter estimation of a human skin-electrode bioelectrical impedance model based on an electrical tactile device is provided. The method is characterized in that: the recursive algorithm with forgetting factor is used, and the data is weighted with the default forgetting factor, so that the new data occupies a greater weight in the parameter estimation; the new input and output dataprovided by the electrical tactile device are used to improve the estimation accuracy, and when the parameters are changed, the estimation is modified to realize online real-time estimation of the parameters; and at the same time, the augmented model is adopted, and the error between the electrical stimulus amount output by the complete and reasonable hypothesis model and the real finger electrical stimulus amount is colored noise, but not the ideal white noise, so that the result is more in line with the actual situation and can adapt to parameter estimation in different noise conditions. The method provided by the present invention avoids the decrease of the parameter correction ability and the interference of the single noise model to the parameter estimation after the recursive step is prolonged, and improves the instantaneity and the accuracy of the finger skin impedance parameter estimation; and the method provided by the present invention is thoughtful, simple and reasonable indesign, easy to implement, and strongly adaptable.

Description

technical field [0001] The invention relates to an impedance parameter estimation method used in the human wrist skin-dermis-subcutaneous tissue electrical impedance model in an electric tactile device, in particular to an epidermis-dermis-subcutaneous tissue electrical impedance model based on a recursive augmented least squares method with a forgetting factor Impedance parameter estimation method in . Background technique [0002] Haptic reproduction refers to stimulating the corresponding sensory parts of people with the tactile information of the remote environment or virtual environment with the help of local haptic devices, so that people can feel various haptic information (pressure, vibration, vibration, etc.) in the remote environment or virtual environment. skin deformation, spatial resolution, sliding sensation, texture, material properties, spatial perception, object stretching). Developed countries and regions such as the United States, Japan and the European U...

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Problems solved by technology

However, none of the above studies fully considered that the human hand-skin impedance model is a time-varying system, because the impedance parameters of the human finger skin will vary with the amplitude and frequency of the current, and will also be affected by the electrode diameter and finger contact area.

In addition, Yantao Shen et al. simplified the human skin-electrode bioimpedance model of the electrotactile device to a first-order model, and estimated the finger skin-electrode impedance model (see: YantaoShen, John Gregory, Ning Xi. Stimulation Current Control for Load- awareElectrotactile haptic rendering: Modeling and Simulation[J].Robotics and Autonomous Systems,2014,62:81~89.), but did not fully consider the model parameters between the finger skin and the electrode

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