Paper: Zebedee: Design of a Spring-Mounted 3-D Range Sensor with Application to Mobile Mapping

October 5th, 2012

Zebedee: Design of a Spring-Mounted 3-D Range Sensor with Application to Mobile Mapping

Three-dimensional perception is a key technology for many robotics applications, including obstacle detection, mapping, and localization. There exist a number of sensors and techniques for acquiring 3-D data, many of which have particular utility for various robotic tasks.

We introduce a new design for a 3-D sensor system, constructed from a 2-D range scanner coupled with a passive linkage mechanism, such as a spring.

The Zebedee scanner in action at Fort Lytton
The Zebedee scanner in action at Fort Lytton

The Zebedee scanner in action at Fort Lytton

By mounting the other end of the passive linkage mechanism to a moving body, disturbances resulting from accelerations and vibrations of the body propel the 2-D scanner in an irregular fashion, thereby extending the device’s field of view outside of its standard scanning plane.

The proposed 3-D sensor system is advantageous due to its mechanical simplicity, mobility, low weight, and relatively low cost. We analyze a particular implementation of the proposed device, which we call Zebedee, consisting of a 2-D time-of-flight laser range scanner rigidly coupled to an inertial measurement unit and mounted on a spring.

The unique configuration of the sensor system motivates unconventional and specialized algorithms to be developed for data processing.

As an example application, we describe a novel 3-D simultaneous localization and mapping solution in which Zebedee is mounted on a moving platform. Using a motion capture system, we have verified the positional accuracy of the sensor trajectory.

The results demonstrate that the six-degree-of-freedom trajectory of a passive spring-mounted range sensor can be accurately estimated from laser range data and industrial-grade inertial measurements in real time and that a quality 3-D point cloud map can be generated concurrently using the same data.

Bosse, R. Zlot, and P. Flick, “Zebedee: Design of a spring- mounted 3-d range sensor with application to mobile mapping,” IEEE Transactions on Robotics, vol. 28, no. 5, pp. 1104–1119, 2012.​