Method and apparatus for state path generation in a controlled system
AssigneeControl Technology Corporation
InventorStanley M. Katz
Life of this patent
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Abstract
Control of time-dependent states, such motion, is facilitated in a manner that avoids explicit solution to the governing equations, but which permits specification of both an initial and a final acceleration. This permits the operator to restrict jerk by exerting control over the final acceleration (e.g., by setting this equal to the initial acceleration, or constraining it to within an allowed maximum), but without explicitly computing parameter values for jerk. More generally, the approach is useful in controlling any system in which states evolve with respect to a specific parameter (frequently, but not necessarily, time), and whose evolution can be described by a defined set of algebraic equations.
Claims12
A method of generating a state path for motion control, the path producing a desired end state specified by desired final values of position, velocity, and acceleration from an initial state, the method comprising the steps of:
- a. defining the motion in terms comprising position, velocity, and acceleration;
- b. relating an initial acceleration to the desired end state in terms of the defined motion;
- and
- c. computing, from the relationship, a required initial acceleration value to achieve the end state.
A method of generating a state path culminating in a desired end state specified by final values of a set of parameters, the parameters including a first variable and first and second derivatives of the first variable with respect to a second variable, the second variable representing an uncontrolled varying parameter, the method comprising the steps of:
- a. defining the path in terms comprising the first variable, and the first and second derivatives of the first variable with respect to the second variable;
- b. relating initial values of the second derivative to final values of the second derivative in terms of the defined path;
- and
- c. computing, from the relationship, a required initial value of the second derivative from the specified final value of the second derivative.
A control system comprising:
- a. a controller for defining a desired motion;
- b. a profile generator for computing at least one state corresponding to at least a portion of the desired motion, the state being specified by desired final values of position, velocity, and acceleration relative to an initial state, the profile generator further computing, from the relationship, a required initial acceleration value from the specified final values of position, velocity, and acceleration;
- and
- c. means for executing the motion based on the required initial acceleration value.
Dependencies are inferred from the claim text.