To enhance encoding efficiency, an unequal error protection （UEP） broadcast scheme based on one additional feedback is proposed. Different from the equal probability selection for source packets in traditional fount...To enhance encoding efficiency, an unequal error protection （UEP） broadcast scheme based on one additional feedback is proposed. Different from the equal probability selection for source packets in traditional fountain encoding, the proposed scheme calculates the packet loss ratio （PLR） according to the feedback results in systematic broadcast phase （SBP） and then optimizes the selection probability for source packets to guarantee higher level error protection for those source packets with larger PLRs. Thus the amount of unnecessarily redundant encoded packets during encoding broadcast phase （EBP） is decreased significantly. Numerical results show that the proposed scheme can recover 60% more packets than the traditional non-feedback broadcast scheme at the ex- pense of tolerably only one feedback procedure.展开更多
A haptic device is proposed which gives the user feedback information on their location and orientation of the obstacle through the mobile robot that detects the obstacle in an environment where the user cannot see.Mo...A haptic device is proposed which gives the user feedback information on their location and orientation of the obstacle through the mobile robot that detects the obstacle in an environment where the user cannot see.Mobile robot recognizes the exact position of the obstacle through configuring the nested ultrasonic sensor and giving feedback information to the haptic device.The haptic device consisting of five vibration motors can realize the haptic through the vibration of user's finger using the position information of the obstacle received feedback.In addition,it has high accuracy to recognize the surrounding environment and realizes the various situations with the fuzzy controller and the nested ultrasonic sensors.展开更多
The equivalent circuit of single-cavity multiple-device fundamentaloscillator(SCMDFO)and that of single-device harmonic oscillator(SDHO)proposed byK.Kurokawa and K.Solbach,respectively,are extended and applied to a si...The equivalent circuit of single-cavity multiple-device fundamentaloscillator(SCMDFO)and that of single-device harmonic oscillator(SDHO)proposed byK.Kurokawa and K.Solbach,respectively,are extended and applied to a single-cavitymultiple-device harmonic oscillator(SCMDHO).By means of describing the functions ofnonlinearity of Gunn diodes,the performances of the SCMDHO are analyzed.It is foundthat the voltage amplitudes are similar to those of SDHO,and the ratio of maximum pow-er of harmonic to that of fundamental is identical to that in SDHO when the devices havesame parameters.The harmonic injection locking behavior is also investigated.The injec-tion locking range is greater than that of SDHO if locking gain remains constant.A2-Gunn diode harmonic oscillator was designed.It delivers 30mW output power at103GHz.The mechanical tuning range is 4.15GHz when the output power remains morethan 10mW.The desired operation mode is stable.展开更多
Background Haptic feedback plays a crucial role in virtual reality(VR)interaction,helping to improve the precision of user operation and enhancing the immersion of the user experience.Instrumental haptic feedback in v...Background Haptic feedback plays a crucial role in virtual reality(VR)interaction,helping to improve the precision of user operation and enhancing the immersion of the user experience.Instrumental haptic feedback in virtual environments is primarily realized using grounded force or vibration feedback devices.However,improvements are required in terms of the active space and feedback realism.Methods We propose a lightweight and flexible haptic feedback glove that can haptically render objects in VR environments via kinesthetic and vibration feedback,thereby enabling users to enjoy a rich virtual piano-playing experience.The kinesthetic feedback of the glove relies on a cable-pulling mechanism that rotates the mechanism and pulls the two cables connected to it,thereby changing the amount of force generated to simulate the hardness or softness of the object.Vibration feedback is provided by small vibration motors embedded in the bottom of the fingertips of the glove.We designed a piano-playing scenario in the virtual environment and conducted user tests.The evaluation metrics were clarity,realism,enjoyment,and satisfaction.Results A total of 14 subjects participated in the test,and the results showed that our proposed glove scored significantly higher on the four evaluation metrics than the nofeedback and vibration feedback methods.Conclusions Our proposed glove significantly enhances the user experience when interacting with virtual objects.展开更多
This paper proposes robot position control using force information for cooperative work between two remote robot systems with force feedback in each of which a user operates a remote robot by using a haptic interface ...This paper proposes robot position control using force information for cooperative work between two remote robot systems with force feedback in each of which a user operates a remote robot by using a haptic interface device while observing work of the robot with a video camera. We also investigate the effect of the proposed control by experiment. As cooperative work, we deal with work in which two robots carry an object together. The robot position control using force information finely adjusts the position of the robot arm to reduce the force applied to the object. Thus, the purpose of the control is to avoid large force so that the object is not broken. In our experiment, we make a comparison among the following three cases in order to clarify how to carry out the control effectively. In the first case, the two robots are operated manually by a user with his/her both hands. In the second case, one robot is operated manually by a user, and the other robot is moved automatically under the proposed control. In the last case, the object is carried directly by a human instead of the robot which is operated by the user in the second case. As a result, experimental results demonstrate that the control can help each system operated manually by the user to carry the object smoothly.展开更多
基金Supported by China National S&T Major Project(2013ZX03003002003)the National Natural Science Foundation of China(61371075)"111"Project of China(B14010)
文摘To enhance encoding efficiency, an unequal error protection （UEP） broadcast scheme based on one additional feedback is proposed. Different from the equal probability selection for source packets in traditional fountain encoding, the proposed scheme calculates the packet loss ratio （PLR） according to the feedback results in systematic broadcast phase （SBP） and then optimizes the selection probability for source packets to guarantee higher level error protection for those source packets with larger PLRs. Thus the amount of unnecessarily redundant encoded packets during encoding broadcast phase （EBP） is decreased significantly. Numerical results show that the proposed scheme can recover 60% more packets than the traditional non-feedback broadcast scheme at the ex- pense of tolerably only one feedback procedure.
基金The MOTIE(Ministry of Trade,Industry and Energy),Korea,under the Human Resources Development Program for Special Environment Navigation Localization National Robotics Research Center support program supervised by the NIPA(National IT Industry Promotion Agency)(H1502-13-1001)The MSIP(Ministry of Science,ICT&Future Planning),Korea,under the ITRC(Information Technology Research Center)support program(NIPA-2013-H0301-13-2006)supervised by the NIPA
文摘A haptic device is proposed which gives the user feedback information on their location and orientation of the obstacle through the mobile robot that detects the obstacle in an environment where the user cannot see.Mobile robot recognizes the exact position of the obstacle through configuring the nested ultrasonic sensor and giving feedback information to the haptic device.The haptic device consisting of five vibration motors can realize the haptic through the vibration of user's finger using the position information of the obstacle received feedback.In addition,it has high accuracy to recognize the surrounding environment and realizes the various situations with the fuzzy controller and the nested ultrasonic sensors.
基金The Project Supported by National Science Foundation of China
文摘The equivalent circuit of single-cavity multiple-device fundamentaloscillator(SCMDFO)and that of single-device harmonic oscillator(SDHO)proposed byK.Kurokawa and K.Solbach,respectively,are extended and applied to a single-cavitymultiple-device harmonic oscillator(SCMDHO).By means of describing the functions ofnonlinearity of Gunn diodes,the performances of the SCMDHO are analyzed.It is foundthat the voltage amplitudes are similar to those of SDHO,and the ratio of maximum pow-er of harmonic to that of fundamental is identical to that in SDHO when the devices havesame parameters.The harmonic injection locking behavior is also investigated.The injec-tion locking range is greater than that of SDHO if locking gain remains constant.A2-Gunn diode harmonic oscillator was designed.It delivers 30mW output power at103GHz.The mechanical tuning range is 4.15GHz when the output power remains morethan 10mW.The desired operation mode is stable.
基金Supported by the Natienal Natural Science Foundation of China(U23A20287).
文摘Background Haptic feedback plays a crucial role in virtual reality(VR)interaction,helping to improve the precision of user operation and enhancing the immersion of the user experience.Instrumental haptic feedback in virtual environments is primarily realized using grounded force or vibration feedback devices.However,improvements are required in terms of the active space and feedback realism.Methods We propose a lightweight and flexible haptic feedback glove that can haptically render objects in VR environments via kinesthetic and vibration feedback,thereby enabling users to enjoy a rich virtual piano-playing experience.The kinesthetic feedback of the glove relies on a cable-pulling mechanism that rotates the mechanism and pulls the two cables connected to it,thereby changing the amount of force generated to simulate the hardness or softness of the object.Vibration feedback is provided by small vibration motors embedded in the bottom of the fingertips of the glove.We designed a piano-playing scenario in the virtual environment and conducted user tests.The evaluation metrics were clarity,realism,enjoyment,and satisfaction.Results A total of 14 subjects participated in the test,and the results showed that our proposed glove scored significantly higher on the four evaluation metrics than the nofeedback and vibration feedback methods.Conclusions Our proposed glove significantly enhances the user experience when interacting with virtual objects.
文摘This paper proposes robot position control using force information for cooperative work between two remote robot systems with force feedback in each of which a user operates a remote robot by using a haptic interface device while observing work of the robot with a video camera. We also investigate the effect of the proposed control by experiment. As cooperative work, we deal with work in which two robots carry an object together. The robot position control using force information finely adjusts the position of the robot arm to reduce the force applied to the object. Thus, the purpose of the control is to avoid large force so that the object is not broken. In our experiment, we make a comparison among the following three cases in order to clarify how to carry out the control effectively. In the first case, the two robots are operated manually by a user with his/her both hands. In the second case, one robot is operated manually by a user, and the other robot is moved automatically under the proposed control. In the last case, the object is carried directly by a human instead of the robot which is operated by the user in the second case. As a result, experimental results demonstrate that the control can help each system operated manually by the user to carry the object smoothly.
