Prof. Zingway Pei Profile

Prof. Zingway Pei

Professor at National Chung Hsing Univ

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Author

Publications (5)

Proceedings Article | 12 September 2019 Presentation

Integration of LiDAR with laser headlight for autonomous driving (Conference Presentation)

Yung-Peng Chang, Hsin-An Chen, Shih-Hsin Chang, Zingway Pei, Chun-Nien Liu, Pin Han, Wood-Hi Cheng

Proceedings Volume 11125, 111250H (2019) https://doi.org/10.1117/12.2526390

KEYWORDS: LIDAR, Headlamps, Control systems, Radar, Ultrasonics, Environmental sensing, Laser development, Integrated optics, Optical imaging, Spectral resolution

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Lidar, radar, optical imaging and ultrasonic are important environmental sensing technologies in the field of autonomous driving. Among them, the radar can perform long-distance sensing, however it is limited by the resolution and cannot distinguish objects. Optical images have clear object resolving power, but hardly to get distance information. Ultrasonic only detect objects that are in very short distances. Therefore, it is necessary to have a technique that can clearly distinguish the objects and get the object information such as speed and distance at medium-range (100-m) for autonomous driving scheme entering level 4 and level 5. The existing light technology in the autonomous driving is to place the Lidar module on the roof of a car and perform environment sensing in a rotating manner. Such technology has low sensing capability and is not conform to the development direction of the vehicle industry that not fulfill the demand of autonomous car. In contrast to Lidar module on the roof, placing the Lidar on the front of the car has many advantages, such as easy to collect dust, suffer water corrosion and difficult to set up the electrical system. Integrating the Lidar with headlight system is a feasible direction to solve the aforementioned problems. In this study, we will develop laser headlights system with Lidar module by integrating the optical system of Lidar into headlight a unit, in which the smart laser headlight was achieved by feedback control orders system. The laser headlight will focus on the development of smart headlights with laser as the light source. With the feedback of the system, it can control the car's light field, avoid high-reflection areas at night. The integrated Lidar module will develop a quasi-static optical scanning system with a wavelength of 1550 nm and embed it in the optical path of the laser headlight. By wavelength differences, the optical path of Lidar does not interfere with headlight and high quality optical data could be obtained. Despite adapting 905 nm as optical wavelength in the current technology, the 1550 nm wavelength selected by this study meets the safety regulations and will not cause damage to the human eye at night or during the day. In this study, we will develop a Lidar module attached to a 10W laser headlight for autonomous driving. The simulation and optical performance of integration of Lidar module with laser headlight will be presented.

Proceedings Article | 9 September 2019 Presentation

Analysis on the 1550nm beam-steering behavior in the linear optical-phased array emitters for lidar application (Conference Presentation)

Zingway Pei, Jheng-Yong Jhong

Proceedings Volume 11105, 111050X (2019) https://doi.org/10.1117/12.2529298

KEYWORDS: Beam steering, LIDAR, Phased array optics, Optical arrays, Environmental sensing, Robotics, Agriculture, Microelectromechanical systems, Mirrors, Reliability

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Light detection and ranging (LiDAR) is an important technique for three-dimensional environment reconstruction that is useful for self-driving car, robotic vehicle, agriculture detection and blind guidance. Beam steering in the current LiDAR is accomplished by a mechanical spinning architecture, which is heavy, slow and expensive. Micro-electrical-mechanical system (MEMS) built mirror is an alternative solution to reduce size and cost. However, the mechanical beam steering in both techniques cause reliability issues in long-term precise beam positioning that limit the broad application of the LiDAR. Optical phased arrayed (OPA) comprise periodic placed emitters with coherent light output by using Silicon photonics. The beam steering in the OPA is accomplished by the interference of coherent light that has no moving parts. Each emitter is modulated and delayed by a pre-determined phase that cause the maximum light intensity has an angle to the emitter plane. This angle is determined by the phase difference in each emitter. Therefore, the beam steering is implemented and controlled by the phase adopted. However, according to the interference theory, second and high-order maximum, the side-lobes, appear at different angles that confuse the LiDAR system by multiple positioning at the same time. In addition, to implement wide angle beam steering, the large amounts of arrayed emitters should be applied. To keep coherent, multiple -3dB light coupling structure were applied. The wide distributed and non-uniform light output between emitters cause the beam steering disturbed. In this work, instead of wide angle beam steering, we design a linear optical phased array (LOPA) with limited number and closed-distance emitters for small angle beam steering. Practical-wise, multiple LOPA modules could be integrated to implement wide angle beam steering. Finite-element method was used to simulate the 1550 nm beam steering behavior in LOPA. With proper and minimal phase delayed, the intensity of the side-lobes was largely suppressed to the primary light. With proper tuning on the sensitivity of the receiver, the high-order disturbance in the LOPA for LiDAR could be eliminated.