Abstract: A system for guiding an autonomous or semi-autonomous vehicle through a field of operation having obstacles thereon to be avoided employs a memory for containing data which defines an array of grid cells which correspond to respective subfields in the field of operation of the vehicle. Each grid cell in the memory contains a value which is indicative of the likelihood, or probability, that an obstacle is present in the respectively associated subfield. The values in the grid cells are incremented individually in response to each scan of the subfields, and precomputation and use of a look-up table avoids complex trigonometric functions. A further array of grid cells is fixed with respect to the vehicle form a conceptual active window which overlies the incremented grid cells. Thus, when the cells in the active window overly grid cell having values which are indicative of the presence of obstacles, the value therein is used as a multiplier of the precomputed vectorial values.

Abstract: Functional electrical stimulation of regions of the skin of disabled individuals is achieved by delivering an energizing electrical signal via an electrode located in the region where the development of pressure sores is desired to be inhibited. Such electrical stimulation produces pressure variations as a result of tissue undulation at the interface where the skin of the human being meets a surface, such as the seat of a wheelchair. Additionally, blood flow is increased, muscles operate as blood pumps, and tissue bulk is increased. Electrical stimulation can be used to improve the conditioning of muscles of individuals who have been disabled for a long period of time, and the muscles have consequently atrophied, so that the beneficial effects of electrical stimulation to prevent or reduce the possibility of pressure sores is achieved.