Seiichiro Mizuno

1 ms column parallel vision system and its application of high speed target tracking

We have developed a 1 ms vision system, to provide a much faster frame rate than that of the conventional systems. Our 1 ms vision system has a 128/spl times/128 PD array and an all parallel processor array connected to each other in a column parallel architecture, so that the bottleneck of an image transfer is solved. 1 ms visual feedback has been realized in this system, in which the image feature value is extracted in 1 ms cycle-time for visual servoing. We have also developed a high speed active vision system (AVS)-II. Finally, we provide a detail discussion on our 1 ms vision system and its performance through some experiments.

A high-speed CMOS image sensor with profile data acquiring function

We have developed a Profile Imager aimed at high-speed automatic target tracking. The Profile Imager can perform both target tracking within a 512 /spl times/ 512-pixel entire image area and acquisition of partial images simultaneously and independently. Experimental results of capturing 128 /spl times/ 128-pixel partial images of an automobile license plate at 1620 frames/s are presented. In addition, results of integrating 89 partial images demonstrate the capability of the device as a high-speed, high-resolution, high-dynamic-range image tracker. A 0.6-/spl mu/m two-poly three-metal CMOS process is used to implement a 13.0 mm /spl times/ 14.3 mm imager.

A 3.2 kHz, 14-Bit Optical Absolute Rotary Encoder With a CMOS Profile Sensor

We have developed a 3.2 kHz, 14-bit optical absolute rotary encoder system using a profile sensor and a slit disc. The profile sensor, which we have designed for this purpose, is a unique CMOS area image sensor aimed at high-speed position detection of X and Y axes. Y axis profile data from the profile sensor is used for recognition of an index code on the slit disc, and X axis profile data is used for position detection of the index code. This combination of two-axis information enables high resolution even with a small number of index codes (64 indexes) and a small amount of digital calculations. Experimental results show that this system can detect rotation with an angular resolution of 14 bits (0.022deg) and a maximum detection speed of 3.2 kHz.

A 256/spl times/256 compact CMOS image sensor with on-chip motion detection function

A 256/spl times/256 CMOS passive pixel image sensor with especially equipped simple switches, which enables motion detection, is implemented. Each pixel consists of a simple combination of a photodiode and an address switch. Photocharge generated at each pixel is converted to voltage by means of a column charge amplifier array, and motion detection has been realized with utilizing the photodiode as a frame memory. Its output is transformed to a digital value with a 128 array 8-bit analog-to-digital (A/D) converter. Simultaneously, fixed pattern noise is suppressed by utilizing A/D conversion as the CDS circuit. Due to its simple structure, more than 70% fill factor ratio has been realized. The extracted motion detection results can be displayed digitally at 128 frames per second by means of 128 A/D converter arrays.

Column parallel vision system (CPV) for high-speed 2D image analysis

In order to overcome the limitation of the image processing speed of the conventional video camera system, we have designed and constructed a column parallel vision (CPV) system. The CPV system realizes an intelligent and general purpose image processing capability with higher frame rate within 1 millisecond (i.e. 1000 frames/s). The system mainly consists of three parts; a sensing unit, a parallel processing unit and a control unit. The sensing unit has a 128x128 photodiode (PD) array, 128-column parallel amplifier array and A/D converter array to achieve high-speed frame rate and has been integrated in a CMOS chip. The parallel processing unit is composed of fully 128x128 processing elements (PEs) to perform a real-time image processing. The control unit has functions of PD/PE control and interface to the host computer. We have confirmed that the CPV system can process general image processing functions within a few ten microseconds. We have also demonstrated that the system can be worked as a tracking system with high-speed feedback loop and have evaluated the accuracy of the position calculation for the desired target.

A high-speed, profile data acquiring image sensor

A profile imager for high-speed automatic target tracking has the capability of executing both target-tracking control from a 512/spl times/512 image array of 20 /spl mu/m/spl times/20 /spl mu/m pixels and the acquisition of a sub-array, simultaneously. 128/spl times/128 partial images of an automobile license plate can be captured at 1620f/s. A 0.6 /spl mu/m 3M2P CMOS process is used to implement the 13.0mm/spl times/14.3mm imager.

A 3.2 kHz, 13-bit Optical Absolute Rotary Encoder with a CMOS Profile Sensor

We have developed a 3.2 kHz, 13-bit optical absolute rotary encoder system using a profile sensor and a slit disc. The profile sensor, which we have designed for this purpose, is a unique CMOS area image sensor aimed at highspeed position detection of X and Y-axes. The profile data of Y-axis from the profile sensor is used for recognition of an index code number of a slit disc and that of X-axis is used for position detection of the index code. This combination of both axes information enables to achieve high resolution even with less number of index codes (64 indexes) and small amount of digital calculations. Experimental results assure that this system can detect 13 bit angle resolution (0.044 degree) and the speed of detection reaches at maximum 3.2 kHz.

Column parallel vision system: CPV

We have designed and constructed a column parallel vision (CPV) system to realize an intelligent and general purpose image processing system with higher frame rate within 1 millisecond. The system consists of an original designed photo detector array (PDA) with high frame rate, a parallel processing unit with fully parallel processing elements (PEs), and a controller for PDA and PEs. The column parallel architecture enables the PDA 1 millisecond frame rate with 256 analog levels which is required for industrial image processing and measurements. The parallel processing unit has been fabricated by using FPGAs and has 128 X 128 PEs to perform the fully parallel image processing. The PEs have the S3PE architecture which has SIMD type parallel processing flow, and was constructed only 500 transistors suitable for integration in future. Since the PEs are operated by control signal from the controller, we can achieve desired image processing task to the system by changing the software. We have demonstrated that the system can be worked as a tracking system. The experimental results show the system was realized high speed feedback loop as 1000 frame/s including the tracking operation with noise reduction, matching (self-window algorithm) and moment calculation.

3D realtime imaging system with PSD array combined with charge amplifier array

A new combination of PSD (Position Sensitive Device) array sensor and newly developed analog CMOS IC to capture an objects 3 dimensional shape is proposed. The CMOS charge sensitive amplifiers are designed to read out the PSD signal current with high speed and accuracy. The CMOS IC which consists of 256 individual charge sensitive amplifiers with a 100 um pitch. More than 60 dB of Signal-to-Noise (S/N) ratio and less than 3 mV variance of the offset voltage could be obtained. The primary purpose of this new compact combination is to provide handicapped people (blind or legally blind) with a means of recognizing objects without actually coming in contact with them.<<ETX>>