• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.603-605
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• 2005

In this paper, we deal with a calibration method for low cost motion capture sensor using PSD (Position Sensitive Detection). The PSD sensor is employed to measure the direction of incident light from moving markers attached to motion body. To calibrate the PSD optical module, a conventional camera calibration algorithm introduced by Tsai. The 3-dimensional positions of the markers are measured by using stereo camera geometry. From the experimental results, the low cost motion capture sensor can be used in a real time system.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1427-1430
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• 2005

In this paper, the range finder system using a PSD sensor suitable for low-cost localization sensor of a mobile robot. Because the distance-voltage output of a PSD sensor has a non-linear property, the linearizing function is proposed through the experimental characteristics of the sensor. And the characteristics are tested and the distance-voltage data are measured in various colors and materials of object. For a known environment, a mobile robot scans the surroundings using a PSD sensor that can rotate $360^{\circ}$. Finally, the performance and accuracy of the developed system are verified according to the comparison the distance by proposed function with real distance

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.6
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• pp.668-672
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• 2005

In this paper, a distance measuring system using a PSD sensor in proposed, which in suitable for low-cost localization sensor of a mobile robot. Because the distance-voltage output of PSD sensor has a non-linear property, the linearizing function is proposed through the experimental characteristics of the sensor. And the characteristics are tested and the distance-voltage data are measured in various colors and materials of object. The parameters of the proposed function are extracted by using the measured data. Finally, the performance and the accuracy of the developed system are verified according to the comparison of the distance by the proposed function with the real distance.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.583-585
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• 2004

In this paper we will deal with a calibration method for low cost motion capture system using psd(position sensitive detection) optical sensor. To measure the incident direction of the light from LED emitted marker, the PSD is used the output current ratio on the electrode of PSD is proportional with the incident position of the light focused by lens. In order to defect the direction of the light, the current output is converted into digital voltage value by opamp circuits peak detector and AD converter with the digital value the incident position is measured. Unfortunately, due to the non-linearly problem of the circuit poor position accuracy is shown. To overcome such problems, we compensated the non-linearly by using least-square fitting method. After compensated the non-linearly in the circuit, the system showed more enhanced position accuracy.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.582-584
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• 2006

This paper describes a monocular PSD-based motion capture sensor to employ with commercial video game systems such as Microsoft's XBOX and Sony's Playstation II. The system compact, low-cost, and only requires a one-time calibration at the factory. The system includes a PSD(Position Sensitive Detector) and active infrared (IR) LED markers that are placed on the object to be tracked. The PSD sensor is placed in the focal plane of a wide-angle lens. The micro-controller calculates the 3D position of the markers using only the measured intensity and 2D position on the PSD. A series of experiments were performed to evaluate the performance of our prototype system. From the experimental results we see that the proposed system's compact size, low-cost, ease of installation, and high frame rates are suitable for high speed motion tracking in games.

• Journal of Sensor Science and Technology
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• v.17 no.2
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• pp.106-113
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• 2008

Perceiving a 3D moving target is important for automated machines including robots in a factory. Although stereovision or ultrasonic ranging is often employed for the purpose, the former requires high-cost systems, and the latter suffers from low-resolution. In this paper, we propose a PSD sensor array to acquire the 3D profile of an object conveyed by a belt. Rectangular parallelepiped target objects at random positions and orientations are assumed. Nine PSD sensors are configured in a $3{\times}3$ array above the belt, and fired in a sequence so that cross-talk can be avoided. Time gaps among sensor readings are compensated to get a result that is obtainable when sensors' measurements are made simultaneously along a sensing line. The system designed is tested with various objects in experiments.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.507-510
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• 2003

In this paper, optical sensor system using PSD(Position Sensitive Detection) is proposed to obtain the three dimensional position of moving markers attached to human body. To find the coordinates of an moving marrer with stereo vision system, two different sight rays of an moving marker are required. Usually, those are acquired with two optical sensors synchronized at the same time. PSD sensor is used to measure the position of an incidence light in real-time. To get the three-dimension position of light source on moving markers, a conventional camera calibration method are used. In this research, we realized a low cost motion capture system. The proposed system shows high three-dimension measurement accuracy and fast sampling frequency.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.568-570
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• 2004

This paper presents a study of a position finding system using PSD Sensor and Pan/Tilt. The position of PSD(Position Sensitive Detector) sensor is calculated by the degree of pan-tilt and the difference in height between pan-tilt and PSD. For that, the DSP which control pan-tilt is used for precise operation. The PIC microcontroller process PSD sensor data that indicate light incident position. A user using computer can acquire the conditions of pan-tilt and PSD and issue an order.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.71-74
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• 2003

The signal processing algorithm for a PSD(Position Sensitive Detector) using amplitude modulation/demodulation is addressed in this paper. Dark currents and external noises such as daylight and fluorescent lights are eliminated by using amplitude modulation/demodulation and a low pass filter. The proposed amplitude modulation/demodulation method for a PSD sensor is compared with pulse amplitude modulation method. The proposed amplitude modulation is proved to be more accurate and robust than PAM method by analysis and experiments. Multiple measurements using one PSD sensor by amplitude modulation/demodulation is also addressed. The Power variation of light source is compensated by normalization process using a divider.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.724-728
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• 2005

This paper represents a development of a range finder sensor module for indoor 2-D mapping and modified Hough transformation for map building. A range finder sensor module has been developed by using optic PSD (Position Sensitive Detector) sensor array at a low price. While PSD sensor is cost effective and light weighting, it has switching noise and white noise. To remove these noises, we propose a heuristic filter. For line-based map building, also we proposed advanced Hough transformation and navigation algorithm. Some experiments were illustrated for the validity of the developed system.