Abstract
We are developing a hand type multi joint manipulator, which adopts a compact pneumatic cylinder as an actuator. The final goal of this research is to recognize the stiffness of the object and to hold the object with in order to recognize the rigidity of an object, it is necessary to apply a force to the object and measure the displacement and the change in force. However, in order to measure the change in force, it is necessary to install a force sensor in the manipulator, but it is costly. Therefore, by measuring the pressure difference inside the cylinder chamber and calculating the external force from the differential pressure, the force is measured without mounting the force sensor. However, as with the force sensor, the installation of the pressure sensor requires a cost. Hence, in this paper, the pressure observer is designed from the input voltage of the Electro-pneumatic regulator and the position information obtained from the displacement sensor, and the pressure in the cylinder chamber is estimated. Then, an external force was calculated from the estimated pressure, and it was verified whether the estimated external force could be used as a force sensor.
