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A novel high speed air-bearing spindle is proposed as a tool spindle for small diameter of cutting and grinding tools. The spindle vibration at high rotational speed is suppressed by an active aerodynamic bearing incorporated into the spindle. For generating aerodynamic damping force, the wedge angle on the aerodynamic bearing surface is controlled by piezoelectric actuators. By using several control tactics, the effect of the active control of the aerodynamic bearing on the spindle vibration is analyzed. Experimental result shows that the amplitude of the spindle vibration can be suppressed to be 0.1μm at the rotational speed of 50,000 min1 (833Hz). Final goal of the study is to suppress the amplitude of spindle vibration less than 0.1 μm at the rotational speed of 120,000 min1 (2kHz).

A new type of touch probe for measuring small optical parts is proposed. The probe is excited by a piezoelectric actuator in sinusoidal waveform. When the vibrating probe touches an object, harmonic components of the vibration appear in the power spectrum of the probe vibration. When the power of the second harmonic exceeds a threshold level, it is judged that the probe touches the object. Measuring force is small enough for measuring the surface of optical parts. The touch probe is mounted on a small CMM controlled by a PC and evaluated its performance by measuring a standard steel ball.

A binocular robot vision system having an autonomously moving active viewpoint is proposed. By using this active viewpoint, the system constructs a correspondence between the images of a feature points on the right and left retinas easily and calculates the spatial coordinates of the feature points. The system incorporates a function that detects straight lines in an image. To detect lines the system uses Hough transform. The system searches a region surrounded by 4 straight lines. Then the system recognizes the region as a quadrangle. The system constructs a correspondence between the quadrangles in the right and left images. By the use of the result of the constructed correspondence, the system calculates the spatial coordinates of an object. An experiment shows the effect of the line detection using Hough transform, the recognition of the surface of the object and the calculation of the spatial coordinates of the object.