Step-based systems with multiple actuators
AssigneeMarel Limited
InventorIan Holmes
Life of this patent
Estimating the term…
Abstract
In a production line where various operations have to be performed on a unit that is conveyed through or assembled in the line, a control system for a set of actuators is provided that operates in discrete steps to carry out movement in a machine and is required to synchronize at points in speed and position. A controller is provided for each actuator, and a coordinator configured to determine or receive the position of the actuators and to receive or generate data concerning a waypoint, being positions and corresponding speeds for the actuators. The controllers are configured to change the speed of the actuators, and the coordinator starts the movement of at least one actuator on the basis of a point reached by another actuator, so as to achieve the desired synchronization.
Claims15
A control system for coordinating movement of a set of actuators each configured to operate in discrete steps to carry out movement in a machine, the control system, comprising:
- a controller for each actuator, containing a table of values relating times taken to reach each successive step for each actuator during acceleration and deceleration, for loads within capacity of the actuator;
- and
- a coordinator configured to determine or receive a position of each actuator and to receive or generate data concerning a waypoint, being positions and corresponding speeds for the actuators;
- wherein the controllers are further configured to raise, lower or maintain the speeds of the actuators at each step by reference to the respective tables, by calculating a number of steps each actuator must travel to reach the waypoint and by raising, lowering or maintaining respective speeds to ensure each actuator is moving at a desired speed at the waypoint, and
- wherein also the coordinator is configured to start the movement of at least one actuator on the basis of a point reached by another actuator, so that both actuators reach the waypoint at a same time.
A method of controlling a set of step-based actuators to act on respective loads and to operate in discrete steps to carry out movement in a machine, in which, for each actuator, a table is provided of values relating times taken to reach each successive step for each actuator during acceleration and deceleration, for loads within a capacity of the actuator and the actuators are controlled to a desired waypoint, being a desired position and speed for the actuator, by calculating a series of steps by reference to the table, each step being adjacent to the previous step;
- and wherein motion of at least one actuator is started on the basis of a measured position of another actuator, wherein both actuators reach the waypoint at a same time.
A control system for a stepper motor, comprising:
- a storage location for a table of values relating achievable speeds to positions for the motor, starting from stationary, where the positions are adjacent steps in motor movement;
- and
- a controller configured to ascertain or receive the position of the motor and to receive or generate data concerning a waypoint, being a desired future position and speed for the motor;
- wherein the controller is further configured to raise, lower or maintain the speed of the motor at each step by reference to the table in such a way that the motor is moving at the desired speed when the motor reaches the desired position;
- wherein the controller is connected to a coordinator configured to start the movement of at least motor on the basis of a point reached by another motor, so that the motor reaches the waypoint at a same time as the other motor.
Dependencies are inferred from the claim text.