In the field of automation technology, a brushless dc motor controller – also called a position control – is used to precisely move and monitor one or more axes in a machine. The positions are processed serially, i.e., the next processing step is not performed until the previous target position has been precisely reached. The brushless dc motor controller controls the positioning process from one position to another position or a sequence of positioning processes according to a path schematic. It is, therefore, also called a feedforward control or path program control.
By means of fast counter inputs for incremental or absolute encoders, the brushless dc motor controller detects the current position and speed of the respective axis and uses it with the target position to calculate the control deviation. In this case, one speaks of a motion control. In addition, a brushless dc motor controller can include extensive additional functions for receiving, generating and processing messages, for processing position values and for monitoring the travel range limits.
The axes can be moved both electrically as well as pneumatically or hydraulically. The most common variant is the control of servomotors or stepper motors. For applications with multiple axes, a primary, intelligent control unit is usually used that communicates with the lower level systems via what is typically a standardized interface. All axes can thereby be simultaneously coordinated via classic field- or Ethernet-based bus systems.
The standalone version can use self-created sequence programs to independently control entire single-axis systems, thereby rendering a primary, intelligent control unit unnecessary. Positioning controllers can be independent devices, realized as a hardware or software module of a PLC, or integrated in the control software of actuators or drive controllers. The control can be realized as either a point control or as a significantly more complex path control in space. Brushless dc motor controllers in combination with motors from FAULHABER result in precise drive systems for highly dynamic movements.