ABSTRACT
This chapter considers order of control as a property of the controlled system or plant. In this case, the order of control refers to the dynamic relation between displacement of a control device and the behavior of the system being controlled. The control order refers to the number of integrations between the control input to a plant and the output of the plant. A plant with one integration between control input and output is a velocity control system. The challenge of controlling second-order systems may not only reflect the geometry of the motion relations, but it may also reflect the requirement that the controller take into account both the position and velocity of the system. Most physical systems have dynamics that are at least second order. A second-order system requires that a controller have information about both position and velocity. In sum, as the order of control of a system increases, the information-processing requirements on the controller also increase.
