Large aperture at low cost three-dimensional time-of-flight range sensor using scanning micromirrors and synchronous detector switching

Abstract

In this article the problem of achieving fast scanning of a time-of-flight range sensor with a large optical receiver aperture at low system cost is targeted. The presented approach to solve this problem consists of a micromirror-based transmitter unit and a receiver unit consisting of a large aperture lens system with a small field of view and a detector array. A concept, which is called synchronous detector switching, is applied to the detector array. Thereby electronic steering of the small receiver field of view is possible. The overall approach is compared to alternative approaches, and the underlying concept of synchronous detector switching is demonstrated experimentally in an implementation of a three-dimensional time-of-flight range sensor. It is theoretically shown that the presented concept is potentially cheaper than the alternative approaches for applications with a field of view of less than 60×60°. After a discussion of the strengths and limitations of the approach, its effect on broader scientific issues is outlined.

MEMS Mirrors for LiDAR: A Review

“…There are several types of motorized optomechanical scanners. The most common one is built with multiple channels of transmitters and receivers stacked vertically and rotated by a motor to generate a full 360 • FoV with multiple horizontal lines (Figure 2c) [27]. The signals and power may have to be wirelessly transmitted from the rotating part to the base board [25].…”

“…The signals and power may have to be wirelessly transmitted from the rotating part to the base board [25]. Such LiDAR are not power-efficient and are vulnerable to mechanical shock and wear [27]. In addition, their vertical resolution is fixed and dependent on the number of transmitter and receiver channels, so a high vertical resolution is always at the price of high cost.…”

All-Solid-State Beam Steering via Integrated Optical Phased Array Technology

“…Mechanical LiDAR is one of the most common types of LiDAR, and has the characteristics of remote detection and large FOV [18,19]. However, such types of LiDAR are bulky, power-hungry, and vulnerable to mechanical shock [20]. Although many miniaturization efforts have been reported, it is still difficult to meet the requirements of robotic mobile platforms [11].…”

Generation of synthetic Point Clouds for MEMS LiDAR Sensor

“…Thus the motorized optomechanical LiDAR sensors can have a horizontal field of view up to 360° [4,5]. Because of the mechanical movable part, this sensor type is vulnerable to mechanical shock and wear [7]. Besides the motorized optomechanical LiDAR sensors, there are also the solid-state LiDARs, which do not have any movable parts.…”