Tham khảo tài liệu 'electroactive polymers for robotic applications - kim & tadokoro (eds.) part 14', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 254 M. Konyo S. Tadokoro and K. Asaka Figure . The relationship between velocities and sensor outputs Figure shows the example of the relationship between the displacement and the sensor output for the length of 15 mm. The displacements were measured at points 5 mm inside from the free ends. The outputs were generated in the same frequencies as each free vibration and the mutual relationship between the amplitude of vibration and that of output was sufficiently estimated from the result of measurement. However it was confirmed that there the sensor outputs had a phasedelay of approximately 90 toward the displacements. These results suggest that the sensor generates voltages in response to the physical value delayed on the displacement by 90 that is the velocity that is given by the differentiation of the displacement. Figure shows the results of the relationship corresponding to Figure between sensor outputs and velocities which were calculated by the difference of the displacements at each sampling time 1 ms . This figure shows clearly that the phases of the velocity are synchronized exactly with that of the output. Figure shows the relationship of the velocities and the sensor outputs on the 15 mm length of IPMC. These results showed that an excellent linear relationship exists between the sensor output and the velocity of bending motion despite the length of the IPMC. Three-DOF Tactile Sensor A 3-DOF tactile sensor was developed that has four IPMC sensor modules combined in a cross shape and can detect both the velocity and direction of motion of the center tip. The parallel arrangements of IPMC sensors contribute to the sensing ability to detect a multi degree of freedom and to the improvement of sensing accuracy by error correcting with several outputs. This cross-shape structure of the IPMC was also studied as a 3-DOF manipulator 10 . If the electric circuits could be switched to actuator driving circuits the 3-DOF tactile .