actionmeasure
Action measure is a term encountered in several disciplines to denote a quantitative representation of the action chosen or applied in a system. In control theory and robotics, action measure often refers to a scalar cost or energy associated with applying a control input u(t) to a dynamical system. A common definition is the running cost defined as the time integral of a function L that depends on the state x(t) and the action u(t), or a simpler form that uses the norm of the control input, possibly with state-dependent weights. This action measure is used in optimal control and model predictive control to favor low energy or smooth control, to respect actuator limits, and to balance performance against wear and risk. Variants include quadratic costs, norms, or more general penalties.
In reinforcement learning and decision making, action measure can describe the policy-induced measure over actions. For
In mathematics and economics literature, the phrase may also appear as a heuristic for the effect or
See also: cost function, action cost, control theory, reinforcement learning, policy, probability measure.