The human tongue has superior movement and tactile sensations. For individuals with severe disabilities, a tongue operated interface device can be used to operate life-support equipment, such as powered wheelchairs an...The human tongue has superior movement and tactile sensations. For individuals with severe disabilities, a tongue operated interface device can be used to operate life-support equipment, such as powered wheelchairs and robotic manipulators. A joystick-type device can directly translate various tongue motions to external equipment behavior. In addition, the user can interactively communicate with the equipment by tactile feedback. This helps the user to control the equipment safely and skillfully. Considering these factors, in a previous study [1], we developed a novel tongue-operated joystick device with reaction force feedback mechanism. We described the design process including the analysis of human tongue movement and tactile sensations and showed fundamental performances of reaction force feedback with the prototype device. In this study, we discuss the shape of the operational part that is used by the tongue. Two types of operational tools are prepared and their operability and perception of reaction force feedback are compared. Furthermore, we confirm the effectiveness of reaction force feedback to operate the joystick device safely and skillful controlling a mobile robot in an unknown environment.展开更多
This paper proposes a quadrant glitch compensation method to achieve nanometer-level accuracy of contouring control for a feed drive system using linear ball guides.The proposed method is a combination of a modified d...This paper proposes a quadrant glitch compensation method to achieve nanometer-level accuracy of contouring control for a feed drive system using linear ball guides.The proposed method is a combination of a modified disturbance observer(“disturbance suppressor”)and an improved repetitive control scheme.Sinusoidal motion tests with 1 mm amplitude and 0.1 Hz driving frequency were conducted using a single-axis feed drive system to verify the quadrant glitch compensation ability of this method.First,the repeatability of the quadrant glitches in the experimental system was verified,which is the most important characteristic required for compensation via repetitive control.Then,by applying the combination of disturbance suppressor and conventional repetitive control,the amplitudes of the quadrant glitches were decreased to less than 1 nm;in other words,the ratio of the magnitude of the quadrant glitch to the amplitude of the position reference was less than 1/1,000,000.However,for both compensation schemes mentioned before,vibrations were generated when the feed speed increased.Moreover,the amplitudes increased with the number of repetitions.The reason for the vibrations was identified as the repetitive control mechanism.To suppress these vibrations,the repetitive control was applied only to narrowed regimes near the quadrant glitches.Thus,the maximum contouring error was decreased to 2 nm.In addition,the nonlinear spring behavior of the linear ball guides was confirmed to affect the stability of the control systems.展开更多
文摘The human tongue has superior movement and tactile sensations. For individuals with severe disabilities, a tongue operated interface device can be used to operate life-support equipment, such as powered wheelchairs and robotic manipulators. A joystick-type device can directly translate various tongue motions to external equipment behavior. In addition, the user can interactively communicate with the equipment by tactile feedback. This helps the user to control the equipment safely and skillfully. Considering these factors, in a previous study [1], we developed a novel tongue-operated joystick device with reaction force feedback mechanism. We described the design process including the analysis of human tongue movement and tactile sensations and showed fundamental performances of reaction force feedback with the prototype device. In this study, we discuss the shape of the operational part that is used by the tongue. Two types of operational tools are prepared and their operability and perception of reaction force feedback are compared. Furthermore, we confirm the effectiveness of reaction force feedback to operate the joystick device safely and skillful controlling a mobile robot in an unknown environment.
文摘This paper proposes a quadrant glitch compensation method to achieve nanometer-level accuracy of contouring control for a feed drive system using linear ball guides.The proposed method is a combination of a modified disturbance observer(“disturbance suppressor”)and an improved repetitive control scheme.Sinusoidal motion tests with 1 mm amplitude and 0.1 Hz driving frequency were conducted using a single-axis feed drive system to verify the quadrant glitch compensation ability of this method.First,the repeatability of the quadrant glitches in the experimental system was verified,which is the most important characteristic required for compensation via repetitive control.Then,by applying the combination of disturbance suppressor and conventional repetitive control,the amplitudes of the quadrant glitches were decreased to less than 1 nm;in other words,the ratio of the magnitude of the quadrant glitch to the amplitude of the position reference was less than 1/1,000,000.However,for both compensation schemes mentioned before,vibrations were generated when the feed speed increased.Moreover,the amplitudes increased with the number of repetitions.The reason for the vibrations was identified as the repetitive control mechanism.To suppress these vibrations,the repetitive control was applied only to narrowed regimes near the quadrant glitches.Thus,the maximum contouring error was decreased to 2 nm.In addition,the nonlinear spring behavior of the linear ball guides was confirmed to affect the stability of the control systems.
