Teleoperation is of great importance in the area of robotics especially when people's presence at the robot working space is unavailable. It provides an alternative to employ human intelligence in the control of the robot remotely. We establish robotic teleoperation systems with a wearable multimodal fusion device. The device is integrated with 18 low-cost inertial and magnetic measurement units, which cover all segments of the arm and hand. The multimodal fusion algorithm based on extended Kalman filter is deduced to determine the orientations and positions of each segment. Then, the robotic teleoperation systems using the proposed device are designed. The novel teleoperation schemes can be applied for 11DOF robotic arm-hand system and 10DOF robotic arm-hand system, in which the operator's fingers are used for robotic hand teleoperation, and the arms with palm are used for robotic arm teleoperation. Meanwhile, the proposed robotic teleoperation systems are fully realized with a user-friendly human-machine interaction interface. Finally, a series of experiments are conducted with our robotic teleoperation system successfully.
To reduce the irradiation exposure time of inspection personnel inspecting the reactor pressure vessel and other water-filled infrastructure during overhaul period, a remotely operated vehicle (ROV) is developed to help monitor the underwater environment and salvage small parts like bolts and nuts in the reactor pool and other water-filled infrastructure of the nuclear power plants. It is designed to be compact, light and radiation resistant. The depth control strategy based on fuzzy proportion integration differentiation is proposed for the ROV to suspend at any depth of the reactor pool. And the integrated navigation algorithm based on the Kalman filter fuses data from sensors, including sonar, depth gauge, three-axis accelerometer, three-axis gyroscope and three-axis magnetometer. Radiation testing has been conducted to verify ROV's ability to work in the reactor pool and other water-filled infrastructure under the environment of high irradiation. Eventually, field experiment was conducted in the reactor simulation pool of the Daya Bay Nuclear Power Plant, and the result verifies the effectiveness of the depth control algorithm, the integrated navigation algorithm and also the leak tightness of the ROV.
SummaryIn order to make the end of the three-axis platform follow the control command and achieve stable control of the end attitude, an improved orientation vector spherical linear interpolation (SLERP) method is proposed for the requirements, which specifically handles the position of the gimbal lock, so that the platform can move smoothly around the gimbal lock position. A three-axis platform with a camera at the end is set up for the validity of the proposed algorithm. At first, an adaptive speed measurement method based on incremental encoder is introduced, which can automatically adapt to high and low speed, and estimate the ultra-low speed to realize the speed measurement of large dynamic range, and this is used for the motion control of the three-axis platform. Then, the SLERP method for the quaternion interpolation on the starting and ending attitudes represented in quaternion is introduced in detail, and it is continuously improved in response to its existing problems for the platform. Finally, an orientation vector SLERP method is proposed, which uses viscosity factor and rejection factor to adjust the algorithm near the platform’s gimbal lock position. A tracking experiment was designed using the red ball as the following target detected by the designed target tracking algorithm using the camera, which verified the effectiveness of the attitude tracking control based on the proposed improved orientation vector SLERP.
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