Energy-optimized xy positioning (1200)

The software module offers the option of positioning the travel and lifting axes in an energy-optimized manner. In order to understand the functional principle, non-energy-optimized positioning (see chapter Absolute positioning mode (400)) is compared with energy-optimized control in the following section.

In both cases positioning starts when the respective dynamic parameters and the target position were specified and feed enable is set. The InPosition bit indicates when the target position is reached.

INFORMATION

The dynamic parameters (acceleration, deceleration, speed, jerk) and the target positions can no longer be changed once positioning has been started.

Positioning without energy optimization

In an SRS without energy optimization, the travel and lifting axes are started at the same time. Both axes travel at maximum acceleration and maximum deceleration.

A great amount of energy is required for accelerating to maximum speed. The energy absorbed increases quadratically with the speed. Potential energy or recuperated energy is converted into heat in the braking resistor.

Energy-optimized control

The application module coordinates the travel and lifting axes of an SRS in such a way that the energy balance is as favorable as possible. The goal is to make the energy that is generated when decelerating one axis available to the other axis that is currently accelerating. For this purpose, the speed, starting time and brake application time of the axes is adapted without extending the total time of the storage/retrieval process.

The total time of a storage/retrieval process is defined by the axis with the longest travel time (master axis). The travel time depends on the travel distance and the maximum possible acceleration, deceleration, and speed of the respective axis.

Due to a shorter distance or a higher speed, the second axis requires less time for completing the travel job.

It occurs only rarely that both axes need exactly the same time for their travel job. There is no room for optimization in this case.