The use of human hand motions as an effective way to interact with computers/robots, robot manipulation learning and prosthetic hand control is being researched in-depth. This paper proposes a novel and effective multiple sensor based hand motion capture and recognition system. Ten common predefined object grasp and manipulation tasks demonstrated by different subjects are recorded from both the human hand and object points of view. Three types of sensors, including electromyography, data glove and FingerTPS are applied to simultaneously capture the EMG signals, the finger angle trajectories, and the contact force. Recognising different grasp and manipulation tasks based on the combined signals is investigated by using an adaptive directed acyclic graph algorithm, and results of comparative experiments show the proposed system with a higher recognition rate compared with individual sensing technology, as well as other algorithms. The proposed framework contains abundant information from multimodal human hand motions with the multiple sensor techniques, and it is potentially applicable to applications in prosthetic hand control and artificial systems performing autonomous dexterous manipulation.
Focusing on the starting problems of a high-voltage and high-power motor, such as large starting current, low power factor, waste of resources, and lack of harmonic control, this paper proposes a current-limiting soft starting method for a high-voltage and high-power motor. The method integrates functions like autotransformer voltage reduction–current limiting starting, magnetron voltage regulation–current limiting starting, and reactive power compensation during starting, and then the power filtering subsystem is turned on to filter out harmonics in power system as the starting process terminates. According to the current-limiting starting characteristic curve, the topological structure of the integrated device is established and then the functional logic switching strategy is put forward. Afterwards, the mechanisms of current-limiting starting, reactive compensation and dynamic harmonic filtering are analyzed, and the simulation and experimental evaluation are completed. In particular, the direct starting and the current-limiting are performed by developing a simulation system. In addition, a 10 kV/19,000 kW fan-loaded motor of a steel plant is chosen as the subject to verify the performance of the current-limiting soft starting method. As shown by the experimental results, the motor’s starting current is about 2 times that of its rated current, the power factor is raised to over 0.9 after the reactive power compensation, and the harmonic filter can effectively eliminate current harmonics and reduce the total harmonic distortion (THD) of supply currents.
1 December 2004 in Earthquake Engineering and Engineering Vibration
Along with massive applications of power electronic equipment and non-linear loads, harmonic pollutions are becoming more serious than ever. This paper describes a novel electromagnetic coupling reactor based passive power filter with dynamic tuning to quickly eliminate harmony. Firstly, the structure and mathematic model of electromagnetic coupling reactor are presented; secondly, the employed parameters, including electromagnetic coupling reactance converter, primary winding coil, and secondary winding coil are designed based on a stable structure of data; then, the test plat of passive dynamic tunable filter is introduced, as well as the performance test. According to the experimental results, the newly designed electromagnetic coupling reactor can effectively eliminate the harmonies generated by the nonlinear load, greatly reducing the harm caused by harmonics on the grid. By fine-tuning the electromagnetic coupling reactor, the dissonance caused by the change of capacitance and other issues can be effectively solved. Finally, the detailed discussion of this paper is presented, and challenges and new future research are discussed.