The Cosworth Motion Controller (CMC) is a fast and accurate model and vehicle motion controller, running on a real-time EtherCAT® master whilst leveraging the power of the Diablo Datahub for trajectory planning and data aggregation. A key benefit of the CMC is that it provides compatibility with a variety of standard motion drives, as well as all EtherCAT DAQ hardware. The CMC also implements a state machine that can restrict allowable moves depending on vehicle attitude.
The CMC consists of a Diablo service running on the Datahub PC and several software modules running on an EtherCAT master. It is designed to remove hardware dependencies by using four core components that interact with standard EtherCAT hardware:
- CMC OBJECT: accepts motion profiles and commands, returning motion related channel data
- AXIS TO ACTUATOR MAP: performs conversion between axis and actuator space, and vice versa
- COSWORTH ACTUATOR CONTROLLER(s): take actuator targets from the CMC and feedback from motion encoder, providing closed loop actuator control
- IMAGE DATA CACHE: snapshots required data and caches it for transfer to the Diablo Datahub via ADS
Motion control occurs in 2 phases, in the Diablo Datahub and the CMC respectively:
- A profile generator creates an actuator profile, maintaining synchronisation between different axes, meeting all actuator constraints for speed and acceleration
- The profile is passed to the CMC, then fed to an interpolator and deflection controller – feedback signals are filtered and the time delay between actuation and measured feedback handled
- The CMC supports continuous playback motion functionality, which is fully integrated to Diablo:
- A tool is used to create motion profiles
- Profiles are imported as a specific field into one or more steps of the test definition
- Profiles are played when associated steps of test definition are reached