<title>Stopping distance analysis of ladar and stereo for unmanned ground vehicles</title>

Abstract

This paper presents an analysis of stopping distances for an unmanned ground vehicle achievable with selected ladar and stereo video sensors. Based on a stop-to-avoid response to detected obstacles, current passive stereo technology and existing ladars provide equivalent safe driving speeds. Only a proposed high-resolution ladar can detect small (8 inch) obstacles far enough ahead to allow driving speeds in excess of 10 miles per hour. The stopping distance analysis relates safe vehicle velocity to obstacle and sensor pixel sizes.

The modelling and control of the drive system of an Ackermann Robot using GA optimization

“…] When considering a DC motor under loading, the moment of inertia is a combine effect of the motors moment of inertia and the moment of inertia caused by the load therefore, the moment of inertia of a DC motor with load are [11 ]; m Based on the drive torque demanded, with moment of inertia as the new moment of inertia, the characteristic state space model of the drive system as given by [10], are revealed in (14) and (15). Thererfore, the Transfer Function of the rear motor is derived at (16).…”

“…Most of them require guided path, although current developments are eliminating guide paths and are almost achieving a complete autonomous control [5]. Autonomous motion planning without collision with objects around the industry, farm or hospital at cheap cost is a challenge [6]. Inertia in Ackermann robot, poses a barrier to proper control however, during chassis motion unavoidable trajectory deviations between current position and requested trajectory occurs.…”

“…The robot used in this work (Redface) is a four wheel Ackermann robot and is driven by a rear wheel engine. Such robots exhibit all the driving challenges found in rear wheel drive vehicles [11,12]. This design have serious impact on the steering and the control of the entire system.…”

Autonomous mobility for Demo III

“…In order to be certain that our proposed autonomous mobility design meets the Demo III goals, we performed a detailed analysis of the Demo III requirements, which in turn generated sub-requirements which are listed here [2][3] [4]. The results ofour analysis show that the autonomous mobility sensors must minimally meet the following requirements: A 1 10 foot range when traveling 40 mph on a downward 7% grade; A 60 foot range when traveling 20 mph on a downward 30% grade; A 90° Horizontal Field OfView (FOV) to navigate close in; A 40° Horizontal FOV to navigate at long range; A 62° vertical FOV to traverse off-road grades; A range accuracy ofbetter than 5% ofthe distance to the obstacle; The ability to detect negative obstacles wider than 24 inches and deeper than 14 inches; An angular resolution of 0.14°; A minimum response time of500 milliseconds; A I 2 foot rear sensing range for reversing at up to 5 mph; …”