These are the three primary colors. All possible hues, levels of brightness, and levels ofsaturation are made up of these three colors in various ratios. The signals from the threecameras are processed by a microcomputer, and the result is fed to the robot controller.Robotic navigationMobile robots must get around in their environment without wasting motion, with-out running into things, and without tipping over or falling down a flight of stairs.The nature of a robotic navigation system depends on the size of the work area, thetype of robot used, and the sorts of tasks the robot is required to perform. In this sec-tion, we’ll look at a few of the more common methods of robotic navigation.ClinometerA clinometer is a device for measuring the steepness of a sloping surface. Mobile ro-bots use clinometers to avoid inclines that might cause them to tip over or that aretoo steep for them to ascend while carrying a load.The floor in a building is almost always horizontal. Thus, its incline is zero. Butsometimes there are inclines such as ramps. A good example is the kind of ramp usedfor wheelchairs, in which a very small elevation change occurs. A rolling robot can’tclimb stairs, but it might use a wheelchair ramp, provided the ramp isn’t so steep that itwould upset the robot’s balance or cause it to lose its payload.In a clinometer, a transducer produces an electrical signal whenever the device istipped from the horizontal. The greater the angle of incline, the greater the electrical out-put, as shown in the graph of Fig. 34-7A. A clinometer might also show whether an inclinegoes down or up. A downward slope might cause a negative voltage at the transducer out-put, and an upward slope a positive voltage, as shown in the graph at Fig. 34-7B.Robotic navigation657SlopeOutputDownUpPositiveoutputNegativeoutputAB34-7Two types of clinometer. At A, the output voltage is a simple func-tion of slope. At B, upslope causes positive output voltage; downs-lope causes negative output voltage.