http://www.emeraldinsight.com/0143-991X.htm Table of Contents from the most recently published issues of Industrial Robot: An International Journal en-us 2009 Emerald Group Publishing Ltd. http://www.emeraldinsight.com/info/pics/journals/ir-cover-xix.gif 120 157 <B>Abstract:</B><BR/> <B>Purpose</B> - Path planning approaches based on conventional occupancy grid maps is problematic in off-road environment because impassible areas include not only obstacles but also landscapes like ramps and pits. The purpose of this paper is to develop a path planning method in a hybrid grid map, which aims to provide a better solution for outdoor navigation.<B>Design/methodology/approach</B> - A hybrid vision system (HVS) which consists of one stereo vision and one omnidirectional vision is adopted to provide environmental information for 2.5D grid and 2D grid mapping, respectively. An improved planning method originated from conventional D* based search algorithm is proposed for more efficient navigation in such hybrid grid maps.<B>Findings</B> - It is confirmed by simulations and experiments that the path planning in the hybrid grid map is more efficient than that in conventional grid maps. Furthermore, it helps to guarantee a safe exploration for field and planetary robots.<B>Originality/value</B> - This paper proposes path planning approach in a hybrid grid map representing unstructured environment. The map consists of two different grid representations with diverse resolutions and structures, named 2.5D and 2D grids. The navigation process is expected to become efficient by reducing the replanning times and track length. Dr. Jiajun Gu, Prof. Qixin Cao Sun Jul 05 14:15:04 BST 2009 <B>Abstract:</B><BR/> <B>Purpose</B> - This paper aims to propose a suitable motion planning for omni-directional mobile robots (OMR) by taking into account the motion characteristics.<B>Design/methodology/approach</B> - Based on the kinematic and dynamic constraints, the maximum velocity, maximum acceleration and energy consumption of the OMR moving in different directions are analyzed, and the anisotropy of the OMR is presented. In order to obtain the optimal motion, the path that the robot can take in order to avoid the obstacle safely and reach the goal in a shorter path is deduced. According to the novel concept of Anisotropic-Function, the motion direction derived from traditional artificial potential field (tAPF) is regulated.<B>Findings</B> - A combination of the Anisotropic-Function and tAPF method produces high-speed, highly stable and efficient motion when compared to the tAPF. Simulations and experiments have proven the validity and effectiveness of this method.<B>Research limitations/implications</B> - The practical factors, such as friction, were not considered during our computations for energy consumption. Typical problems of APF, for e.g. local minima, are not addressed here. In our future research we will deal with these issues.<B>Practical implications</B> - The proposed motion planning is applicable for any kind of OMR, which can fully exhibit the advantages of OMRs.<B>Originality/value</B> - The novel concept of an Anisotropic-Function is proposed to indicate the quality of motion in different directions, which can make for a very favorable trade-off between time-optimality, stability and efficiency. Different motion effects can be obtained in the same direction with different weights denoted by the Anisotropic-Function, i.e. different trade-offs can be achieved by varying the weights. Dr. Chuntao Leng, Prof. Qixin Cao Sun Jul 05 14:15:04 BST 2009