A Depth Sensing Display for Bomb Disposal Robots
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I. INTRODUCTION
With almost every bomb squad robot there is a lack of an
important perception which is critical when manipulating any
kind of explosive device. Most bomb squad robot graspers in
use do not give the operator a depth reading. Instead, the
robots use multiple cameras to obtain different views and then
the operator must employ various workarounds to gauge the
depth or distances to objects located in the environment.


II. RELATED WORK
Three modalities have been historically used to obtain
depth: (1) planer laser ranger, (2) sonar, and (3) stereovision.
Of the three modalities, only sonar does not appear to have
been applied to robotic graspers. In addition to these
modalities a new sensor system has been developed that is
small and lightweight, a miniature 3D ranger that uses near
infrared laser light. This section describes planer laser rangers,
stereovision, and miniature 3D rangers, then compares
stereovision with miniature 3D rangers.


III. EQUIPMENT
The display developed and tested for this work was designed
for a specific robot and depth sensor, but it is expected to be
applicable to other robot/depth sensor combinations. The
hardware consists of a Remotec Mini-Max robot and a depth
sensor created by Canesta Inc. mounted on the manipulator
arm (see Fig. 3.1a and Fig. 3.1c). Figure 3.1a shows exactly
shows the small size of the Canesta, only 12.7 cm wide.
Figure 3.1b gives a sense of the size of the Mini-Max robot,
the black pelican case is 75 cm long by 52 cm wide. Figure
3.1c displays the Canesta sensor’s mounting in relation to the
robot’s grasper.


Software
The interface design was developed in Java for integration
into a Java-based robotic architecture and for portability.
The Canesta sensor’s drivers were developed in and
designed to be used in C or C++ applications. Java’s JNI
allowed communication between the interface and the
Canesta sensor’s drivers.