Chương 5, vị trí của robot thực tế hoặc servo được gọi là chó săn. Thuật ngữ này xuất phát từ các doanh nghiệp đua chó, một con thỏ cơ khí được điều khiển theo dõi trước các gói của răng nanh đua. Một hệ thống vòng khép kín là một biện pháp lỗi giữa thỏ và chó săn, và cố gắng để giảm thiểu khoảng cách mà không bị thất thường. | Chapter 5 the position of the actual robot or servo is referred to as the hound. This terminology comes from the dog racing business where a mechanical rabbit is driven down the track ahead of the pack of racing canines. A closed loop system is one that measures the error between the rabbit and hound and attempts to minimize the gap without becoming erratic. Classical control theory has been in existence for a very long time. Engineering courses have traditionally taught mathematical techniques involving poles and zeros and very abstract mathematics that beautifully describe the conditions under which a control can be designed with optimal performance. Normally this involves producing a control system that maintains the fastest possible response to changing input functions without becoming underdamped getting the jitters . It is perhaps fortunate that the professor who taught me this discipline has long ago passed from this plane of existence else he would most probably be induced to cause me to do so were he to read what I am about to say. Control theory as it was taught to me obsessed over the response of a system to a step input. Creating a control that can respond to such an input quickly and without overshooting is indeed difficult. Looking back I am reminded of the old joke where the patient lifts his arm over his head and complains to the doctor It hurts when I do this Doc to which the doctor replies Then don t do that. With software controls the first rule is never to command a control to move in a way it clearly cannot track. If you studied calculus you know that position is the integral of velocity velocity is the integral of acceleration and acceleration is the integral of jerk. Calculus involves determining the effect of these parameters upon each other at some future time. In real-time controls this type of prediction is not generally needed. Instead we simply divide time into small chunks accumulating the jerk to provide the acceleration and .
