Robot Programming : A Practical Guide to Behavior-Based Robotics
Language: English
Pages: 288
ISBN: 0071427783
Format: PDF / Kindle (mobi) / ePub
* Teaches the concepts of behavior-based programming through text, programming examples, and a unique online simulator robot
* Explains how to design new behaviors by manipulating old ones and adjusting programming
* Does not assume reader familiarity with robotics or programming languages
* Includes a section on designing your own behavior-based system from scratch
square law in this case. If we want the robot to react to more distant objects, we might use 1/r, rather than 1/r2. Or if we want the robot to ignore obstacles until it is quite close, we could use 1/r3 or an even higher power or r. A force-sensing bumper is analogous to a sonar sensor that computes forces using a high power or r. The bumper completely ignores obstacles until the distance is zero, then the effective repulsive force goes to a value sufficiently large to stop the robot. 1This
the timer has started, then test_timer returns true. In any other situation, test_timer returns false (including testing a timer that has not been created). If the timer is called again before time T seconds have passed, the clock starts over. That is, test_timer always returns true if called within T seconds of the most recent call to start_timer. The timer facility gives us a method for remembering and acting on events that have happened recently, e.g., the detection of an object. The
distance to the part of the beam that strikes a surface first (not the distance measured by the center of the beam). Sonars 0 and 11 received no echo and thus cannot compute an accurate distance. Not indicated in the drawing is the phenomenon that sonar beams striking a surface obliquely sometimes fail to return an echo. Sonar 8, for example, might report no echo. Another method to avoid objects using sonar sensors involves computing a vector sum. Suppose that we imagine (as described in the
is the interpretation of the data they deliver that can be problematic. Is the robot homing on the lamp above the recharging station or is it rather homing on the shaft of late afternoon sunlight streaming through the window? Are all photocells the same? Indeed not; different photocells produce different signals when struck with the same light. Does this matter? Usually it matters less than you might think; see Figure 7.9. The mismatch between a pair of photocells used to implement homing means
and initial heading, all you have to do is count your steps and turn precisely when the step count indicates that you have reached an intersection. This is exactly what our example robot does when it executes the London task. In practice, can you successfully complete your trip? No; your situation is clearly hopeless. Given a map but no possibility of correcting your path along the way, the effects of any tiny mistakes you make early on just grow and grow. After no more than a block or two, you