Novel slope detection and calculation techniques for mobile robots

Modern technologies are rapidly moving towards unmanned systems. Autonomous robots are one of the prime examples of such intelligent systems with numerous applications. The robots need to perceive their surroundings in order to execute assigned tasks. Obstacle detection and collision avoidance are fundamental aspects that are required in mobile robots, for which many schemes have been developed. Obstacles in the way of robots are mainly classified into objects, slopes and ditches. The inclinations of slopes are typically sensed by using tilt sensors for which robots need to climb the inclined surfaces and robots have to experience the tilt themselves. This paper presents two low cost slope detection and calculation techniques by means of ultrasonic range finders. These methods have been successfully implemented on a robot named The ROBUST, allowing it to differentiate between objects and sloppy paths that appear en-route. The concepts can empower robots with abilities of detecting positive as well as negative slopes remotely i.e. sensing slope inclinations and declinations from a suitable distance without climbing or touching the surfaces; thus enabling the aspect of ditch avoidance in them too. Furthermore, experimental results, special applications and limitations of the techniques are discussed in detail.