Soft pressure sensor embedded in McKibben actuator

This study aims at development of intelligent McKibben actuators with embedded soft displacement/pressure sensors and micro valves. In the previous report, development of the rubber displacement sensor incorporated in the McKibben actuator and its application to the position servo system were reported. In this report, the soft pressure sensor made of rubber and conductive film was developed and embedded in the McKibben actuator. By measuring electrical resistance of the conductive film which changes following deformation of the rubber with internal pressure change of the actuator, pressure can be estimated. The results of the fundamental experiments to clear the characteristics of the sensor showed that it has the drift characteristics by the influence of creep behavior of the rubber. Therefore, we tried to apply the mechanical model to the sensor model. 2-Voigt mechanical model which consists of two springs and two dampers could agree the sensor characteristics. Using the model, we carried out the pressure control experiments and the force control experiments of the actuator. The results indicated the efficacy of the model. Furthermore we expect that the modeling method will be able to contribute to improving accuracy of several soft mechanisms.